Kevin Chen - Academia.edu (original) (raw)
Papers by Kevin Chen
ACS applied materials & interfaces, Jan 14, 2018
Interface engineering is a key strategy to deal with the two-dimensional (2D)/three-dimensional (... more Interface engineering is a key strategy to deal with the two-dimensional (2D)/three-dimensional (3D) hybrid heterostructure, since the properties of this atomic-layer-thick 2D material can easily be impacted by the substrate environment. In this work, the structural, electronic, and optical properties of the 2D/3D heterostructure of monolayer MoS on wurtzite GaN surface without and with nitridation interfacial layer are systematically investigated by first-principles calculation and experimental analysis. The nitridation interfacial layer can be introduced into the 2D/3D heterostructure by remote N plasma treatment to GaN sample surface prior to stacking monolayer MoS on top. The calculation results reveal that the 2D/3D integrated heterostructure is energetically favorable with a negative formation energy. Both interfaces demonstrate indirect band gap, which is a benefit for longer lifetime of the photoexcited carriers. Meanwhile, the conduction band edge and valence band edge of t...
Langmuir : the ACS journal of surfaces and colloids, Feb 27, 2018
Surface functionalization of the dangling-bond-free MoS, WSe, and other TMDs (transition metal di... more Surface functionalization of the dangling-bond-free MoS, WSe, and other TMDs (transition metal dichalcogenides) is of large practical importance, for example, in providing nucleation sites for the subsequent high-k dielectric integration. Of the surface functionalization methods, the reversible O or N atom adsorption on top of the chalcogen atoms is most promising. However, hazards such as severe oxidation or nitridation persist when the adsorption coverage is high. An in situ characterization technique, which can be integrated with the surface functionalization and dielectric deposition chamber, becomes valuable to enable the real-time monitoring of surface adsorption conditions. Raman spectroscopy, as a nondestructive characterization method without vacuum requirement, is a strong candidate. By utilizing first-principles calculations, Raman spectra of single-layer MoS and WSe with various O/N adsorption coverages are studied. The calculations suggest that the low-coverage O/N adso...
The Journal of arthroplasty, Jun 9, 2018
Irrigation and debridement (I&D) is performed for early management of periprosthetic joint infect... more Irrigation and debridement (I&D) is performed for early management of periprosthetic joint infection (PJI) following total knee arthroplasty (TKA). Symptom reporting is a subjective measure and may miss direct management of PJI. Utilizing an objective time interval from index procedure to I&D may better inform treatment decisions. From 2009 to 2017, retrospective review was performed of 55 knee PJI cases at our institution. All patients underwent polyethylene liner exchange and I&D for PJI. Patients were stratified by time from index procedure to I&D (≤2 weeks, >2 weeks). Success was defined as eradication of infection and resolution of presenting symptoms. Failed cases required subsequent procedures due to infection. Average follow-up time after index TKA was 2.5 years. Among patients with I&D within 2 weeks of index TXA, 14 patients (82%) were successfully treated while 3 (18%) had infection recurrence. These outcomes were significantly improved compared to patients with I&D af...
Physical review letters, Jan 9, 2018
We experimentally demonstrate topological edge states arising from the valley-Hall effect in two-... more We experimentally demonstrate topological edge states arising from the valley-Hall effect in two-dimensional honeycomb photonic lattices with broken inversion symmetry. We break the inversion symmetry by detuning the refractive indices of the two honeycomb sublattices, giving rise to a boron nitridelike band structure. The edge states therefore exist along the domain walls between regions of opposite valley Chern numbers. We probe both the armchair and zigzag domain walls and show that the former become gapped for any detuning, whereas the latter remain ungapped until a cutoff is reached. The valley-Hall effect provides a new mechanism for the realization of time-reversal-invariant photonic topological insulators.
The Orthopedic clinics of North America, 2018
The objective of this study was to evaluate the efficacy of respiratory synchronized compression ... more The objective of this study was to evaluate the efficacy of respiratory synchronized compression devices (RSCDs) versus nonsynchronized intermittent pneumatic compression devices (NSIPCDs) in preventing venous thromboembolism (VTE) after total joint arthroplasty. A systematic literature review was conducted. Data regarding surgical procedure, deep vein thrombosis, pulmonary embolism, mortality, and adverse events were abstracted. Compared with control groups, the risk ratio of deep vein thrombosis development was 0.51 with NSIPCDs and 0.47 with RSCDs. This review demonstrates that RSCDs may be marginally more effective at preventing VTE events than NSIPCDs. Furthermore, the addition of mechanical prophylaxis to any chemoprophylactic regimen increases VTE prevention.
Retina (Philadelphia, Pa.), Jan 16, 2018
To compare retinal pathology visualization in multispectral scanning laser ophthalmoscope imaging... more To compare retinal pathology visualization in multispectral scanning laser ophthalmoscope imaging between the Spectralis and Optos devices. This retrospective cross-sectional study included 42 eyes from 30 patients with age-related macular degeneration (19 eyes), diabetic retinopathy (10 eyes), and epiretinal membrane (13 eyes). All patients underwent retinal imaging with a color fundus camera (broad-spectrum white light), the Spectralis HRA-2 system (3-color monochromatic lasers), and the Optos P200 system (2-color monochromatic lasers). The Optos image was cropped to a similar size as the Spectralis image. Seven masked graders marked retinal pathologies in each image within a 5 × 5 grid that included the macula. The average area with detected retinal pathology in all eyes was larger in the Spectralis images compared with Optos images (32.4% larger, P < 0.0001), mainly because of better visualization of epiretinal membrane and retinal hemorrhage. The average detection rate of ag...
The Journal of arthroplasty, Jan 21, 2018
At our institution, all postoperative total hip arthroplasty (THA) candidates have received home ... more At our institution, all postoperative total hip arthroplasty (THA) candidates have received home health services (HHS), consisting of visiting nurses, physical and occupational therapists. However, with a more technologically inclined patient population, electronic patient rehabilitation applications (EPRAs) can be used to deliver perioperative care at the comfort of the patient's home. The aim of this study is to investigate the clinical utility and economic burden associated with digital rehabilitation applications in primary THA recipients. We conducted a single-center, retrospective review of patients operated between November 2016 and November 2017. Before surgery, and at the discretion of the surgeon, patients were assigned to EPRA with HHS or EPRA alone. Patient baseline demographics, EPRA engagement, and validated patient-reported outcomes (PROs) were (Veterans Rand 12-Item Health Survey [VR-12] and Hip Disability and Osteoarthritis Outcome Score Junior) at baseline and ...
American journal of men's health, 2018
Internet gaming is a legitimate leisure activity worldwide; however, there are emerging concerns ... more Internet gaming is a legitimate leisure activity worldwide; however, there are emerging concerns that vast numbers of gamers are becoming addicted. In 2013, the American Psychiatric Association (APA) classified Internet Gaming Disorder (IGD) as a condition warranting more clinical research ahead of formalizing it as a mental disorder. Proposed as a behavioral addiction, IGD shares many similarities in both physical and psychosocial manifestations with substance use disorder, including cerebral changes on functional magnetic resonance imaging (fMRI). Among the gaming population, compared to females, adolescent and adult males demonstrate far more addictive internet gaming use in terms of screen hours, craving, and negative impacts on health, which have, in isolated incidents, also caused death. The current article draws findings from a scoping review of literature related to IGD as a means to raising awareness about an emergent men's health issue. Included are three themes: (a) u...
The Journal of arthroplasty, Jan 16, 2017
The Bundled Payments for Care Improvement initiative was developed to reduce costs associated wit... more The Bundled Payments for Care Improvement initiative was developed to reduce costs associated with total joint arthroplasty through a single payment for all patient care from index admission through a 90-day post-discharge period, including care at skilled nursing facilities (SNFs). The aim of this study is to investigate whether forming partnerships between hospitals and SNFs could lower the post-discharge costs. We hypothesize that institutionally aligned SNFs have lower post-discharge costs than non-aligned SNFs. A cohort of 615 elective, primary total hip and knee arthroplasty subjects discharged to an SNF under the Bundled Payments for Care Improvement from 2014 to 2016 were included in our analysis. Patients were grouped into one of the 3 categories of SNF alignment: group 1: non-partners; group 2: agreement-based partners; group 3: institution-owned partners. Demographics, comorbidities, length of stay (LOS) at SNF, and associated costs during the 90-day post-operative period...
Journal of glaucoma, Jan 17, 2017
To report the first successful implantation of a CyPass supraciliary stent combined with two targ... more To report the first successful implantation of a CyPass supraciliary stent combined with two targeted iStent trabecular microbypass stents in a phakic primary open angle glaucoma patient with markedly elevated intraocular pressures (IOP) on maximum tolerable medical therapy. Case report. A 52-year-old phakic male patient with primary open-angle glaucoma (POAG) with uncontrolled IOP in the right eye (OD) of 36 mm Hg on maximal topical pharmacotherapy. The patient underwent implantation of a single CyPass supraciliary stent combined with the targeted implantation of two iStent trabecular microbypass stents, one right facing stent and one left facing stent. Postoperatively, off of all glaucoma medications, the IOP decreased to 10 mm Hg on day one and continued to be controlled between 10-13 mm Hg until post-operative month 6, with only one glaucoma medication added after post-operative month 5. Additionally, there were no post-operative complications to date. The combined implantation ...
Arthroplasty Today
Background: The use of perioperative surgical wound dressings is an important factor in the mitig... more Background: The use of perioperative surgical wound dressings is an important factor in the mitigation of infection following total joint arthroplasty (TJA). Few studies have been published comparing wound dressings and infection rates after TJA. Methods: MEDLINE, PubMed, and EMBASE were searched for studies published between 2006 and 2016 reporting infection rates in patients using various wound dressings after undergoing TJA. All studies comparing Hydrofibre dressings to Standard dressings or Absorbent dressings were included in this meta-analysis. Studies looking at TJA secondary to trauma were excluded. Two individuals independently extracted data, and study results were divided based on type of treatment. The primary outcome was to compare the infection rate of Hydrofibre dressings to that of both Standard Dressings and Absorbent dressings. Results: Of a total of 3721 participants, 1483 were treated with Standard dressings (non-impregnated gauze), 1911 with Hydrofibre dressings, and 327 with Absorbent dressings. The risk ratio for infection comparing Standard with Hydrofibre was 4.16 (95% confidence interval, 1.71-10.16) as compared to 2.60 (95% confidence interval, 0.66-10.27) when comparing Absorbent with Hydrofibre dressings. Conclusions: Our analysis suggests that Hydrofibre dressings may be significantly better than Standard and Absorbent dressings with respect to reducing infection. However, given the observed heterogeneity and small number of studies included, more comparative studies are needed to definitively recommend superiority among dressings following TJA.
The Journal of arthroplasty, Jan 3, 2017
Chronic opioid users pose a unique challenge for orthopedic surgeons, as they often report subopt... more Chronic opioid users pose a unique challenge for orthopedic surgeons, as they often report suboptimal outcomes following total knee arthroplasty (TKA). We aim at identifying risk factors associated with patients who were preoperative chronic opioid users and continued to use 6 months following TKA. All preoperative chronic opioid users among 338 consecutive TKA cases performed at our institution between February and June 2016 were identified and divided into 2 cohorts: patients who (1) persistently used opioids and (2) discontinued use by the 6-month time point following surgery. Baseline characteristics were compared between cohorts in order to determine risk factors for persistent opioid use following TKA. Of the 338 patients, 53 (15.7%) were identified as preoperative chronic opioid users. Of these, 23 (43.4%) continued chronic opioid use 6 months following surgery, whereas 14 (4.9%) previously nonchronic users were identified as new chronic users at 6 months. Characteristics tha...
Survey of ophthalmology, Jan 3, 2017
A 54-year-old white man presented with a "blind spot" temporally in his left eye. Best-... more A 54-year-old white man presented with a "blind spot" temporally in his left eye. Best-corrected visual acuity in the affected eye was 20/20 and Humphrey visual field revealed an enlarged blind spot. Funduscopic examination revealed subtle peripapillary pigmentary changes corresponding to a well-demarcated peripapillary region of hyper- and hypoautofluorescence on fundus autofluorescence (FAF). Outer retinal degenerative changes were detected on spectral domain optical coherence tomography (SD-OCT). A diagnosis of Acute zonal occult outer retinopathy (AZOOR) was made based on clinical history and imaging studies.
ACS sensors, Jan 27, 2017
A distributed sensing capable high temperature D-shaped optical fiber modified with a palladium n... more A distributed sensing capable high temperature D-shaped optical fiber modified with a palladium nanoparticle sensitized mesoporous (∼5 nm) TiO2 film, is demonstrated. The refractive index of the TiO2 film was reduced using block copolymer templating in order to realize a mesoporous matrix, accommodating integration with optical fiber. The constructed sensor was analyzed by performing direct transmission loss measurements, and by analyzing the behavior of an integrated fiber Bragg grating. The inscribed grating should reveal whether the refractive index of the composite film experiences changes upon exposure to hydrogen. In addition, with frequency domain reflectometry the distributed sensing potential of the developed sensor for hydrogen concentrations of up to 10% is examined. The results show the possibility of detecting chemical gradients with sub-cm resolution at temperatures greater than 500 °C.
Journal of the American Chemical Society, Jun 21, 2017
This paper describes the supramolecular assembly of a macrocyclic β-sheet containing residues 16-... more This paper describes the supramolecular assembly of a macrocyclic β-sheet containing residues 16-22 of the β-amyloid peptide, Aβ. X-ray crystallography reveals that the macrocyclic β-sheet assembles to form double-walled nanotubes, with an inner diameter of 7 nm and outer diameter of 11 nm. The inner wall is composed of an extended network of hydrogen-bonded dimers. The outer wall is composed of a separate extended network of β-barrel-like tetramers. These large peptide nanotubes pack into a hexagonal lattice that resembles a honeycomb. The complexity and size of the peptide nanotubes rivals some of the largest tubular biomolecular assemblies, such as GroEL and microtubules. These observations demonstrate that small amyloidogenic sequences can be used to build large nanostructures.
Retina (Philadelphia, Pa.), Jan 16, 2017
To describe atypical cases of multiple evanescent white dot syndrome (MEWDS) associated with fove... more To describe atypical cases of multiple evanescent white dot syndrome (MEWDS) associated with foveal exudation, increased choroidal thickness, and secondary Type 2 (subretinal) neovascularization. Four cases of atypical MEWDS were studied at a retina referral center. Patients underwent evaluation with multimodal retinal imaging, including fluorescein angiography, indocyanine green angiography, spectral-domain and enhanced depth imaging optical coherence tomography (OCT). Two patients were imaged with OCT angiography. Four patients (3 female, 1 male) with a median age of 23.5 years presented with acute onset, painless, decreased central vision. All cases demonstrated fundus findings consistent with MEWDS on color photography, indocyanine green angiography, fluorescein angiography, fundus autofluorescence, and structural OCT imaging. On structural OCT, all 4 patients were noted to have hyperreflective subretinal material and increased subfoveal choroidal thickness ranging from 307 μm t...
Oncotarget, Jan 2, 2016
Peripheral T-cell lymphomas (PTCLS) comprise a diverse group of difficult to treat, very aggressi... more Peripheral T-cell lymphomas (PTCLS) comprise a diverse group of difficult to treat, very aggressive non-Hodgkin's lymphomas (NHLS) with poor prognoses and dismal patient outlook. Despite the fact that PTCLs comprise the majority of T-cell malignancies, the standard of care is poorly established. Chimeric antigen receptor (CAR) immunotherapy has shown in B-cell malignancies to be an effective curative option and this extends promise into treating T-cell malignancies. Because PTCLS frequently develop from mature T-cells, CD3 is similarly strongly and uniformly expressed in many PTCL malignancies, with expression specific to the hematological compartment thus making it an attractive target for CAR design. We engineered a robust 3rd generation anti-CD3 CAR construct (CD3CAR) into an NK cell line (NK-92). We found that CD3CAR NK-92 cells specifically and potently lysed diverse CD3+ human PTCL primary samples as well as T-cell leukemia cells lines ex vivo. Furthermore, CD3CAR NK-92 ce...
Journal of medicinal chemistry, Jun 18, 2016
Our previously reported structures of calpain bound to its endogenous inhibitor calpastatin have ... more Our previously reported structures of calpain bound to its endogenous inhibitor calpastatin have motivated the use of aziridine aldehyde-mediated peptide macrocyclization toward the design of cyclic peptides and peptidomimetics as calpain inhibitors. Inspired by nature's hint that a β-turn loop within calpastatin forms a broad interaction around calpain's active site cysteine, we have constructed and tested a library of 45 peptidic compounds based on this loop sequence. Four molecules have shown reproducibly low micromolar inhibition of calpain-2. Further systematic sequence changes led to the development of probes that displayed increased potency and specificity of inhibition against calpain over other cysteine proteases. Calculated Ki values were in the low micromolar range, rivaling other peptidomimetic calpain inhibitors and presenting an improved selectivity profile against other therapeutically relevant proteases. Competitive and mixed inhibition against calpain-2 was ...
American journal of ophthalmology, Jan 8, 2016
To describe the natural course, visual outcomes and anatomic changes and provide histological cor... more To describe the natural course, visual outcomes and anatomic changes and provide histological correlates in eyes with intraretinal hyperreflective foci associated with acquired vitelliform lesions. Retrospective cohort study and imaging-histology correlation in a single donor eye. Participants: Patients with intraretinal hyperreflective foci and acquired vitelliform lesions from two tertiary referral centers were evaluated from January 2002-January 2014. The chronology of clinical and imaging features of retinal anatomic changes and the pattern of intraretinal hyperreflective foci migration were documented using spectral-domain optical coherence tomography (OCT). One donor eye with intraretinal hyperreflective foci was identified in a pathology archive by ex vivo OCT and was studied with high-resolution light and electron microscopic examination. Intraretinal hyperreflective foci were associated with acquired vitelliform lesions in 25 of 254 eyes (9.8%) with a strong female preponde...
ACS applied materials & interfaces, Jan 14, 2018
Interface engineering is a key strategy to deal with the two-dimensional (2D)/three-dimensional (... more Interface engineering is a key strategy to deal with the two-dimensional (2D)/three-dimensional (3D) hybrid heterostructure, since the properties of this atomic-layer-thick 2D material can easily be impacted by the substrate environment. In this work, the structural, electronic, and optical properties of the 2D/3D heterostructure of monolayer MoS on wurtzite GaN surface without and with nitridation interfacial layer are systematically investigated by first-principles calculation and experimental analysis. The nitridation interfacial layer can be introduced into the 2D/3D heterostructure by remote N plasma treatment to GaN sample surface prior to stacking monolayer MoS on top. The calculation results reveal that the 2D/3D integrated heterostructure is energetically favorable with a negative formation energy. Both interfaces demonstrate indirect band gap, which is a benefit for longer lifetime of the photoexcited carriers. Meanwhile, the conduction band edge and valence band edge of t...
Langmuir : the ACS journal of surfaces and colloids, Feb 27, 2018
Surface functionalization of the dangling-bond-free MoS, WSe, and other TMDs (transition metal di... more Surface functionalization of the dangling-bond-free MoS, WSe, and other TMDs (transition metal dichalcogenides) is of large practical importance, for example, in providing nucleation sites for the subsequent high-k dielectric integration. Of the surface functionalization methods, the reversible O or N atom adsorption on top of the chalcogen atoms is most promising. However, hazards such as severe oxidation or nitridation persist when the adsorption coverage is high. An in situ characterization technique, which can be integrated with the surface functionalization and dielectric deposition chamber, becomes valuable to enable the real-time monitoring of surface adsorption conditions. Raman spectroscopy, as a nondestructive characterization method without vacuum requirement, is a strong candidate. By utilizing first-principles calculations, Raman spectra of single-layer MoS and WSe with various O/N adsorption coverages are studied. The calculations suggest that the low-coverage O/N adso...
The Journal of arthroplasty, Jun 9, 2018
Irrigation and debridement (I&D) is performed for early management of periprosthetic joint infect... more Irrigation and debridement (I&D) is performed for early management of periprosthetic joint infection (PJI) following total knee arthroplasty (TKA). Symptom reporting is a subjective measure and may miss direct management of PJI. Utilizing an objective time interval from index procedure to I&D may better inform treatment decisions. From 2009 to 2017, retrospective review was performed of 55 knee PJI cases at our institution. All patients underwent polyethylene liner exchange and I&D for PJI. Patients were stratified by time from index procedure to I&D (≤2 weeks, >2 weeks). Success was defined as eradication of infection and resolution of presenting symptoms. Failed cases required subsequent procedures due to infection. Average follow-up time after index TKA was 2.5 years. Among patients with I&D within 2 weeks of index TXA, 14 patients (82%) were successfully treated while 3 (18%) had infection recurrence. These outcomes were significantly improved compared to patients with I&D af...
Physical review letters, Jan 9, 2018
We experimentally demonstrate topological edge states arising from the valley-Hall effect in two-... more We experimentally demonstrate topological edge states arising from the valley-Hall effect in two-dimensional honeycomb photonic lattices with broken inversion symmetry. We break the inversion symmetry by detuning the refractive indices of the two honeycomb sublattices, giving rise to a boron nitridelike band structure. The edge states therefore exist along the domain walls between regions of opposite valley Chern numbers. We probe both the armchair and zigzag domain walls and show that the former become gapped for any detuning, whereas the latter remain ungapped until a cutoff is reached. The valley-Hall effect provides a new mechanism for the realization of time-reversal-invariant photonic topological insulators.
The Orthopedic clinics of North America, 2018
The objective of this study was to evaluate the efficacy of respiratory synchronized compression ... more The objective of this study was to evaluate the efficacy of respiratory synchronized compression devices (RSCDs) versus nonsynchronized intermittent pneumatic compression devices (NSIPCDs) in preventing venous thromboembolism (VTE) after total joint arthroplasty. A systematic literature review was conducted. Data regarding surgical procedure, deep vein thrombosis, pulmonary embolism, mortality, and adverse events were abstracted. Compared with control groups, the risk ratio of deep vein thrombosis development was 0.51 with NSIPCDs and 0.47 with RSCDs. This review demonstrates that RSCDs may be marginally more effective at preventing VTE events than NSIPCDs. Furthermore, the addition of mechanical prophylaxis to any chemoprophylactic regimen increases VTE prevention.
Retina (Philadelphia, Pa.), Jan 16, 2018
To compare retinal pathology visualization in multispectral scanning laser ophthalmoscope imaging... more To compare retinal pathology visualization in multispectral scanning laser ophthalmoscope imaging between the Spectralis and Optos devices. This retrospective cross-sectional study included 42 eyes from 30 patients with age-related macular degeneration (19 eyes), diabetic retinopathy (10 eyes), and epiretinal membrane (13 eyes). All patients underwent retinal imaging with a color fundus camera (broad-spectrum white light), the Spectralis HRA-2 system (3-color monochromatic lasers), and the Optos P200 system (2-color monochromatic lasers). The Optos image was cropped to a similar size as the Spectralis image. Seven masked graders marked retinal pathologies in each image within a 5 × 5 grid that included the macula. The average area with detected retinal pathology in all eyes was larger in the Spectralis images compared with Optos images (32.4% larger, P < 0.0001), mainly because of better visualization of epiretinal membrane and retinal hemorrhage. The average detection rate of ag...
The Journal of arthroplasty, Jan 21, 2018
At our institution, all postoperative total hip arthroplasty (THA) candidates have received home ... more At our institution, all postoperative total hip arthroplasty (THA) candidates have received home health services (HHS), consisting of visiting nurses, physical and occupational therapists. However, with a more technologically inclined patient population, electronic patient rehabilitation applications (EPRAs) can be used to deliver perioperative care at the comfort of the patient's home. The aim of this study is to investigate the clinical utility and economic burden associated with digital rehabilitation applications in primary THA recipients. We conducted a single-center, retrospective review of patients operated between November 2016 and November 2017. Before surgery, and at the discretion of the surgeon, patients were assigned to EPRA with HHS or EPRA alone. Patient baseline demographics, EPRA engagement, and validated patient-reported outcomes (PROs) were (Veterans Rand 12-Item Health Survey [VR-12] and Hip Disability and Osteoarthritis Outcome Score Junior) at baseline and ...
American journal of men's health, 2018
Internet gaming is a legitimate leisure activity worldwide; however, there are emerging concerns ... more Internet gaming is a legitimate leisure activity worldwide; however, there are emerging concerns that vast numbers of gamers are becoming addicted. In 2013, the American Psychiatric Association (APA) classified Internet Gaming Disorder (IGD) as a condition warranting more clinical research ahead of formalizing it as a mental disorder. Proposed as a behavioral addiction, IGD shares many similarities in both physical and psychosocial manifestations with substance use disorder, including cerebral changes on functional magnetic resonance imaging (fMRI). Among the gaming population, compared to females, adolescent and adult males demonstrate far more addictive internet gaming use in terms of screen hours, craving, and negative impacts on health, which have, in isolated incidents, also caused death. The current article draws findings from a scoping review of literature related to IGD as a means to raising awareness about an emergent men's health issue. Included are three themes: (a) u...
The Journal of arthroplasty, Jan 16, 2017
The Bundled Payments for Care Improvement initiative was developed to reduce costs associated wit... more The Bundled Payments for Care Improvement initiative was developed to reduce costs associated with total joint arthroplasty through a single payment for all patient care from index admission through a 90-day post-discharge period, including care at skilled nursing facilities (SNFs). The aim of this study is to investigate whether forming partnerships between hospitals and SNFs could lower the post-discharge costs. We hypothesize that institutionally aligned SNFs have lower post-discharge costs than non-aligned SNFs. A cohort of 615 elective, primary total hip and knee arthroplasty subjects discharged to an SNF under the Bundled Payments for Care Improvement from 2014 to 2016 were included in our analysis. Patients were grouped into one of the 3 categories of SNF alignment: group 1: non-partners; group 2: agreement-based partners; group 3: institution-owned partners. Demographics, comorbidities, length of stay (LOS) at SNF, and associated costs during the 90-day post-operative period...
Journal of glaucoma, Jan 17, 2017
To report the first successful implantation of a CyPass supraciliary stent combined with two targ... more To report the first successful implantation of a CyPass supraciliary stent combined with two targeted iStent trabecular microbypass stents in a phakic primary open angle glaucoma patient with markedly elevated intraocular pressures (IOP) on maximum tolerable medical therapy. Case report. A 52-year-old phakic male patient with primary open-angle glaucoma (POAG) with uncontrolled IOP in the right eye (OD) of 36 mm Hg on maximal topical pharmacotherapy. The patient underwent implantation of a single CyPass supraciliary stent combined with the targeted implantation of two iStent trabecular microbypass stents, one right facing stent and one left facing stent. Postoperatively, off of all glaucoma medications, the IOP decreased to 10 mm Hg on day one and continued to be controlled between 10-13 mm Hg until post-operative month 6, with only one glaucoma medication added after post-operative month 5. Additionally, there were no post-operative complications to date. The combined implantation ...
Arthroplasty Today
Background: The use of perioperative surgical wound dressings is an important factor in the mitig... more Background: The use of perioperative surgical wound dressings is an important factor in the mitigation of infection following total joint arthroplasty (TJA). Few studies have been published comparing wound dressings and infection rates after TJA. Methods: MEDLINE, PubMed, and EMBASE were searched for studies published between 2006 and 2016 reporting infection rates in patients using various wound dressings after undergoing TJA. All studies comparing Hydrofibre dressings to Standard dressings or Absorbent dressings were included in this meta-analysis. Studies looking at TJA secondary to trauma were excluded. Two individuals independently extracted data, and study results were divided based on type of treatment. The primary outcome was to compare the infection rate of Hydrofibre dressings to that of both Standard Dressings and Absorbent dressings. Results: Of a total of 3721 participants, 1483 were treated with Standard dressings (non-impregnated gauze), 1911 with Hydrofibre dressings, and 327 with Absorbent dressings. The risk ratio for infection comparing Standard with Hydrofibre was 4.16 (95% confidence interval, 1.71-10.16) as compared to 2.60 (95% confidence interval, 0.66-10.27) when comparing Absorbent with Hydrofibre dressings. Conclusions: Our analysis suggests that Hydrofibre dressings may be significantly better than Standard and Absorbent dressings with respect to reducing infection. However, given the observed heterogeneity and small number of studies included, more comparative studies are needed to definitively recommend superiority among dressings following TJA.
The Journal of arthroplasty, Jan 3, 2017
Chronic opioid users pose a unique challenge for orthopedic surgeons, as they often report subopt... more Chronic opioid users pose a unique challenge for orthopedic surgeons, as they often report suboptimal outcomes following total knee arthroplasty (TKA). We aim at identifying risk factors associated with patients who were preoperative chronic opioid users and continued to use 6 months following TKA. All preoperative chronic opioid users among 338 consecutive TKA cases performed at our institution between February and June 2016 were identified and divided into 2 cohorts: patients who (1) persistently used opioids and (2) discontinued use by the 6-month time point following surgery. Baseline characteristics were compared between cohorts in order to determine risk factors for persistent opioid use following TKA. Of the 338 patients, 53 (15.7%) were identified as preoperative chronic opioid users. Of these, 23 (43.4%) continued chronic opioid use 6 months following surgery, whereas 14 (4.9%) previously nonchronic users were identified as new chronic users at 6 months. Characteristics tha...
Survey of ophthalmology, Jan 3, 2017
A 54-year-old white man presented with a "blind spot" temporally in his left eye. Best-... more A 54-year-old white man presented with a "blind spot" temporally in his left eye. Best-corrected visual acuity in the affected eye was 20/20 and Humphrey visual field revealed an enlarged blind spot. Funduscopic examination revealed subtle peripapillary pigmentary changes corresponding to a well-demarcated peripapillary region of hyper- and hypoautofluorescence on fundus autofluorescence (FAF). Outer retinal degenerative changes were detected on spectral domain optical coherence tomography (SD-OCT). A diagnosis of Acute zonal occult outer retinopathy (AZOOR) was made based on clinical history and imaging studies.
ACS sensors, Jan 27, 2017
A distributed sensing capable high temperature D-shaped optical fiber modified with a palladium n... more A distributed sensing capable high temperature D-shaped optical fiber modified with a palladium nanoparticle sensitized mesoporous (∼5 nm) TiO2 film, is demonstrated. The refractive index of the TiO2 film was reduced using block copolymer templating in order to realize a mesoporous matrix, accommodating integration with optical fiber. The constructed sensor was analyzed by performing direct transmission loss measurements, and by analyzing the behavior of an integrated fiber Bragg grating. The inscribed grating should reveal whether the refractive index of the composite film experiences changes upon exposure to hydrogen. In addition, with frequency domain reflectometry the distributed sensing potential of the developed sensor for hydrogen concentrations of up to 10% is examined. The results show the possibility of detecting chemical gradients with sub-cm resolution at temperatures greater than 500 °C.
Journal of the American Chemical Society, Jun 21, 2017
This paper describes the supramolecular assembly of a macrocyclic β-sheet containing residues 16-... more This paper describes the supramolecular assembly of a macrocyclic β-sheet containing residues 16-22 of the β-amyloid peptide, Aβ. X-ray crystallography reveals that the macrocyclic β-sheet assembles to form double-walled nanotubes, with an inner diameter of 7 nm and outer diameter of 11 nm. The inner wall is composed of an extended network of hydrogen-bonded dimers. The outer wall is composed of a separate extended network of β-barrel-like tetramers. These large peptide nanotubes pack into a hexagonal lattice that resembles a honeycomb. The complexity and size of the peptide nanotubes rivals some of the largest tubular biomolecular assemblies, such as GroEL and microtubules. These observations demonstrate that small amyloidogenic sequences can be used to build large nanostructures.
Retina (Philadelphia, Pa.), Jan 16, 2017
To describe atypical cases of multiple evanescent white dot syndrome (MEWDS) associated with fove... more To describe atypical cases of multiple evanescent white dot syndrome (MEWDS) associated with foveal exudation, increased choroidal thickness, and secondary Type 2 (subretinal) neovascularization. Four cases of atypical MEWDS were studied at a retina referral center. Patients underwent evaluation with multimodal retinal imaging, including fluorescein angiography, indocyanine green angiography, spectral-domain and enhanced depth imaging optical coherence tomography (OCT). Two patients were imaged with OCT angiography. Four patients (3 female, 1 male) with a median age of 23.5 years presented with acute onset, painless, decreased central vision. All cases demonstrated fundus findings consistent with MEWDS on color photography, indocyanine green angiography, fluorescein angiography, fundus autofluorescence, and structural OCT imaging. On structural OCT, all 4 patients were noted to have hyperreflective subretinal material and increased subfoveal choroidal thickness ranging from 307 μm t...
Oncotarget, Jan 2, 2016
Peripheral T-cell lymphomas (PTCLS) comprise a diverse group of difficult to treat, very aggressi... more Peripheral T-cell lymphomas (PTCLS) comprise a diverse group of difficult to treat, very aggressive non-Hodgkin's lymphomas (NHLS) with poor prognoses and dismal patient outlook. Despite the fact that PTCLs comprise the majority of T-cell malignancies, the standard of care is poorly established. Chimeric antigen receptor (CAR) immunotherapy has shown in B-cell malignancies to be an effective curative option and this extends promise into treating T-cell malignancies. Because PTCLS frequently develop from mature T-cells, CD3 is similarly strongly and uniformly expressed in many PTCL malignancies, with expression specific to the hematological compartment thus making it an attractive target for CAR design. We engineered a robust 3rd generation anti-CD3 CAR construct (CD3CAR) into an NK cell line (NK-92). We found that CD3CAR NK-92 cells specifically and potently lysed diverse CD3+ human PTCL primary samples as well as T-cell leukemia cells lines ex vivo. Furthermore, CD3CAR NK-92 ce...
Journal of medicinal chemistry, Jun 18, 2016
Our previously reported structures of calpain bound to its endogenous inhibitor calpastatin have ... more Our previously reported structures of calpain bound to its endogenous inhibitor calpastatin have motivated the use of aziridine aldehyde-mediated peptide macrocyclization toward the design of cyclic peptides and peptidomimetics as calpain inhibitors. Inspired by nature's hint that a β-turn loop within calpastatin forms a broad interaction around calpain's active site cysteine, we have constructed and tested a library of 45 peptidic compounds based on this loop sequence. Four molecules have shown reproducibly low micromolar inhibition of calpain-2. Further systematic sequence changes led to the development of probes that displayed increased potency and specificity of inhibition against calpain over other cysteine proteases. Calculated Ki values were in the low micromolar range, rivaling other peptidomimetic calpain inhibitors and presenting an improved selectivity profile against other therapeutically relevant proteases. Competitive and mixed inhibition against calpain-2 was ...
American journal of ophthalmology, Jan 8, 2016
To describe the natural course, visual outcomes and anatomic changes and provide histological cor... more To describe the natural course, visual outcomes and anatomic changes and provide histological correlates in eyes with intraretinal hyperreflective foci associated with acquired vitelliform lesions. Retrospective cohort study and imaging-histology correlation in a single donor eye. Participants: Patients with intraretinal hyperreflective foci and acquired vitelliform lesions from two tertiary referral centers were evaluated from January 2002-January 2014. The chronology of clinical and imaging features of retinal anatomic changes and the pattern of intraretinal hyperreflective foci migration were documented using spectral-domain optical coherence tomography (OCT). One donor eye with intraretinal hyperreflective foci was identified in a pathology archive by ex vivo OCT and was studied with high-resolution light and electron microscopic examination. Intraretinal hyperreflective foci were associated with acquired vitelliform lesions in 25 of 254 eyes (9.8%) with a strong female preponde...