Nay Myo Tun - Academia.edu (original) (raw)

Papers by Nay Myo Tun

GaAlAs (N)/GaAs (p⁺)/GaAlAs (N) Double Heterojunction Bipolar Transistor (DHBTs) with single regr... more GaAlAs (N)/GaAs (p⁺)/GaAlAs (N) Double Heterojunction Bipolar Transistor (DHBTs) with single regrown base (p⁺ -GaAs or p⁺ -Ga₀.₈Al₀.₂As), double regrown base (p⁺) -GaAs /p⁺ -Ga₀.₈Al₀.₂As) and diffused base have been designed and fabricated by Liquid Phase Epitaxy (LPE) super cooling technique. Most of DHBTs with the single regrown base and diffused base showed the asymmetrical (I, V) characteristics with normal mode gain of 10-40 and inverted mode gain of 5-18. The offset voltage was in between 100mV to 600mV which conformed to the large difference between the CB and EB junction voltages. The asymmetric characteristics with high offset voltage are owing to either high electron injections from the collector to the external base region under inverted mode and then loss by recombination in GaAs (p⁺) regrown base or high intrinsic recombination centers in the Ga₀.₈Al₀.₂As (p⁺) external base layer. Moreover some DHBTs with single regrown base exhibited a knee-shape characteristic in inve...

BACKGROUND Sister Mary Joseph nodule refers to metastatic malignancy of the periumbilical region.... more BACKGROUND Sister Mary Joseph nodule refers to metastatic malignancy of the periumbilical region. Umbilical metastasis is an indicator of advanced malignant disease. CASE REPORT We present the case of an 88-year-old patient presenting with postmenopausal vaginal bleeding, inguinal lymphadenopathy, and physical findings of a palpable umbilical nodule (Sister Mary Joseph nodule). Further workup was consistent with metastatic squamous cell carcinoma of the cervix. CONCLUSION Because Sister Mary Joseph nodule may be the only manifestation of underlying malignancy, thorough physical examination plays an important role in diagnosing the malignancy in a more confined state that may have a positive impact on the patient's length of survival.

Free radical research, 2014

Amino acid biosynthesis forms part of an integrated stress response against oxidants in Saccharom... more Amino acid biosynthesis forms part of an integrated stress response against oxidants in Saccharomyces cerevisiae and higher eukaryotes. Here we show an essential protective role of the l-lysine biosynthesis pathway in response to the oxidative stress condition induced by the lipid oxidant-linoleic acid hydroperoxide (LoaOOH), by means of transcriptomic profiling and phenotypic analysis, and using the deletion mutant dal80∆ and lysine auxotroph lys1∆. A comprehensive up-regulation of lysine biosynthetic genes (LYS1, LYS2, LYS4, LYS9, LYS12, LYS20 and LYS21) was revealed in dal80Δ following the oxidant challenge. The lysine auxotroph (lys1∆) exhibited a significant decrease in growth compared with that of BY4743 upon exposure to LoaOOH, albeit with the sufficient provision of lysine in the medium. Furthermore, the growth of wild type BY4743 exposed to LoaOOH was also greatly reduced in lysine-deficient conditions, despite a full complement of lysine biosynthetic genes. Amino acid anal...

Blood coagulation & fibrinolysis : an international journal in haemostasis and thrombosis, 2015

Antiphospholipid syndrome (APS) and heparin-induced thrombocytopenia (HIT) are thrombotic disorde... more Antiphospholipid syndrome (APS) and heparin-induced thrombocytopenia (HIT) are thrombotic disorders due to specific autoimmune-mediated antibodies. Catastrophic APS (CAPS), also known as Asherman's syndrome, is a life-threatening severe form of APS. Diagnostic criteria for CAPS include the development of a thrombotic event of three or more organs in less than a week with the presence of antiphospholipid antibodies and microvascular thrombosis on histology. Thrombocytopenia is seen in more than 60% of cases of CAPS. HIT is a life-threatening disorder with the clinical presentation of thrombocytopenia and arterial or venous thrombosis in patients who develop antibodies to heparin and platelet factor 4 typically within 10 days after starting heparin treatment. Due to the multiple similarities in clinical features and pathophysiology of CAPS and HIT, it has been postulated that these two antibody-mediated disorders may be related. We report two cases in which patients diagnosed with...

Journal of Community Hospital Internal Medicine Perspectives, 2014

Whipple's disease is a systemic infectious disease caused by the bacteria Tropheryma whipplei. Th... more Whipple's disease is a systemic infectious disease caused by the bacteria Tropheryma whipplei. The most common clinical manifestations of Whipple's disease are weight loss (92%), hypoalbuminemia and steatorrhea (91%, respectively), diarrhea (72%), arthralgia (67%), and abdominal pain (55%). Neurological signs and symptoms from dementia to oculomasticatory myorhythmia or oculofacioskeletal myorhythmia (pathognomonic of Whipple's disease), lymphadenopathy, and fatigue can also be present. Pancytopenia is a rare and less recognized clinical feature in Whipple's disease patients. We are describing a case where a middle-aged Caucasian male diagnosed with Whipple's disease was found to have pancytopenia. Etiology of pancytopenia is postulated to be due to the invasion of bone marrow by T. whipplei. It is important to recognize that bone marrow involvement by the Whipple bacillus is not uncommon. In the presence of lymphadenopathy and pancytopenia, clinicians should think of Whipple's disease as a differential diagnosis apart from lymphoma or other non-specific granulomatous reticuloendothelial disorders.

SPIE Proceedings, 2004

Bidirectional (mutual) injection locking was demonstrated with solid-state lasers, producing sign... more Bidirectional (mutual) injection locking was demonstrated with solid-state lasers, producing significant improvements over traditional single-direction injection locking. Each laser element shares part of its output with other elements in bidirectional locking, distinct from single-direction (traditional) injection locking where one master laser provides the locking signal for a number of slaves. In a phase-locked array, the individual laser outputs add coherently, and the brightness of the entire array scales with the square of the number of elements, as if the active material diameter were increasing. Benefits of bidirectional locking, when compared to traditional injection locking, include reduced laser threshold, better output beam quality, and improved scaling capability. Experiments using two Nd:YVO 4 lasers confirmed that mutual injection locking reduced lasing threshold by a factor of at least two and increased the output beam quality significantly. The injection locking effects began with 0.03% coupling between lasers and full-phase locking for coupling exceeding 0.5%. The 0.5% requirement for full phase-locking limits traditional injection-locked arrays to fewer than 100 elements, while mutually injection-locked arrays have no such limit. Mutual injection locking of an array of lasers can lead to a new architecture for high-power laser systems.

World Journal of Oncology, 2013

A 53-year-old woman was diagnosed with splenic marginal zone lymphoma by pathological examination... more A 53-year-old woman was diagnosed with splenic marginal zone lymphoma by pathological examination on left submandibular lymph node and bone marrow biopsies and markedly enlarged spleen. Four cycles of Rituximab chemotherapy were given. Seven months after finishing Rituximab chemotherapy, she developed left upper extremity swelling without evidence of deep venous thrombosis. Repeat PET/CT scan demonstrated multiple left axillary lymph nodes extending to left retroclavicular region and a new lymph node posterior to the left scapula. Biopsy of the lymph node demonstrated marginal zone lymhoma pattern with increased numbers of large cells, but not outright diffuse large B-cell lymphoma. Despite resuming rituximab, patient had persistent leukocytosis and severe anemia. Restaging PET/CT showed 3 new left anterior cervical lymph nodes and 1 new right axillary lymph node. Spleen has further enlarged. R-CHOP chemotherapy was started, which improved leukocytosis. After 4 cycles of R-CHOP, PET/CT showed new metabolic activity within right inguinal and abdominal lymph nodes. Patient was given one cycle of Bendamustine. She developed a possible "hematoma" in right medial elbow. However, MRI study revealed a subcutaneous deposit of the lymphoma. Patient needs consistently blood transfusion and she deteriorated quickly. Our patient had an aggressive course of splenic marginal zone lymphoma, not responding to four trials of chemotherapy although SMZL is well-known to be an indolent low grade lymphoma. This case report emphasizes the importance to individualize the treatment in SMZL patients and repeat bone marrow biopsy if the disease recurs.

Metallomics, 2014

Genome-wide screening using gene deletion mutants has been widely carried out with numerous toxic... more Genome-wide screening using gene deletion mutants has been widely carried out with numerous toxicants including oxidants and metal ions. The focus of such studies usually centres on identifying sensitive phenotypes against a given toxicant. Here, we screened the complete collection of yeast gene deletion mutants (5047) with increasing concentrations of aluminium sulphate (0.4, 0.8, 1.6 and 3.2 mM) in order to discover aluminium (Al(3+)) tolerant phenotypes. Fifteen genes were found to be associated with Al(3+) transport because their deletion mutants exhibited Al(3+) tolerance, including lem3Δ, hal5Δ and cka2Δ. Deletion of CKA2, a catalytic subunit of tetrameric protein kinase CK2, gives rise to the most pronounced resistance to Al(3+) by showing significantly higher growth compared to the wild type. Functional analysis revealed that both molecular regulation and endocytosis are involved in Al(3+) transport for yeast. Further investigations were extended to all the four subunits of CK2 (CKA1, CKA2, CKB1 and CKB2) and the other 14 identified mutants under a spectrum of metal ions, including Al(3+), Zn(2+), Mn(2+), Fe(2+), Fe(3+), Co(3+), Ga(3+), Cd(2+), In(3+), Ni(2+) and Cu(2+), as well as hydrogen peroxide and diamide, in order to unravel cross-tolerance amongst metal ions and the effect of the oxidants. Finally, the implication of the findings in Al(3+) transport for the other species like plants and humans is discussed.

Indian Journal of Hematology and Blood Transfusion, 2014

Multisensor, Multisource Information Fusion: Architectures, Algorithms, and Applications 2005, 2005

Advances in the development of imaging sensors depend upon (among other things) the testing capab... more Advances in the development of imaging sensors depend upon (among other things) the testing capabilities of research laboratories. Sensors and sensor suites need to be rigorously tested under laboratory and field conditions before being put to use. Real-time dynamic simulation of real targets is a key component of such testing, as actual full-scale tests with real targets are extremely expensive and time consuming and are not suitable for early stages of development. Dynamic projectors simulate tactical images and scenes. Several technologies exist for projecting IR and visible scenes to simulate tactical battlefield patterns-large format resistor arrays, liquid crystal light valves, Eidophor type projecting systems, and micromirror arrays, for example. These technologies are slow, or are restricted either in the modulator array size or in spectral bandwidth. In addition, many operate only in specific bandwidth regions. Physical Optics Corporation is developing an alternative to current scene projectors. This projector is designed to operate over the visible, near-IR, MWIR, and LWIR spectra simultaneously, from 300 nm to 20 m. The resolution is 2 megapixels, and the designed frame rate is 120 Hz (40 Hz in color). To ensure high-resolution visible imagery and pixel-to-pixel apparent temperature difference of 100°C, the contrast between adjacent pixels is >100:1 in the visible to near-IR, MWIR, and LWIR. This scene projector is designed to produce a flickerless analog signal, suitable for staring and scanning arrays, and to be capable of operation in a hardware-in-the-loop test system. Tests performed on an initial prototype demonstrated contrast of 250:1 in the visible with non-optimized hardware.

SPIE Proceedings, 2005

Head-mounted or helmet-mounted displays (HMDs) have long proven invaluable for many military appl... more Head-mounted or helmet-mounted displays (HMDs) have long proven invaluable for many military applications. Integrated with head position, orientation, and/or eye-tracking sensors, HMDs can be powerful tools for training. For such training applications as flight simulation, HMDs need to be lightweight and compact with good center-of-gravity characteristics, and must display realistic full-color imagery with eye-limited resolution and large field-of-view (FOV) so that the pilot sees a truly realistic out-the-window scene. Under bright illumination, the resolution of the eye is ~300 r (1 arc-min), setting the minimum HMD resolution. There are several methods of achieving this resolution, including increasing the number of individual pixels on a CRT or LCD display, thereby increasing the size, weight, and complexity of the HMD; dithering the image to provide an apparent resolution increase at the cost of reduced frame rate; and tiling normal resolution subimages into a single, larger high-resolution image. Physical Optics Corporation (POC) is developing a 5120 4096 pixel HMD covering 1500 1200 mr with resolution of 300 r by tiling 20 subimages, each of which has a resolution of 1024 1024 pixels, in a 5 4 array. We present theory and results of our preliminary development of this HMD, resulting in a 4k 1k image tiled from 16 subimages, each with resolution 512 512, in an 8 2 array.

F1000Research, 2014

Objective: The antenatal prevalence of syphilis and HIV/AIDS in migrants and refugees is poorly d... more Objective: The antenatal prevalence of syphilis and HIV/AIDS in migrants and refugees is poorly documented. The aim of this study was to audit the first year of routine syphilis screening in migrant and refugee women on the Thai Myanmar border.Methods: From August 2012 to July 2013, 3600 pregnant women were screened for HIV (ELISA) and syphilis (VDRL with TPHA confirmation) at clinics along the Thai-Myanmar border.Results: Seroprevalence for HIV 0.47% (95% CI 0.30-0.76) (17/3,599), and syphilis 0.39% (95% CI 0.23-0.65) (14/3,592), were low. Syphilis was significantly lower in refugees (0.07% 95% CI 0.01-0.38) (1/1,469), than in migrants (0.61% 95% CI 0.36-1.04) (13/2,123). The three active (VDRL≥1:8 and TPHA reactive) syphilis cases with VDRL titres of 1:32 were easy to counsel and treat. Women with low VDRL titres (>75% were < 1:8) and TPHA reactive results, in the absence of symptoms and both the woman and her husband having only one sexual partner in their lifetime, and the...

Journal of Thrombosis and Thrombolysis, 2014

ABSTRACT

Cockpit and Future Displays for Defense and Security, 2005

True 3D displays, whether generated by volume holography, merged stereopsis (requiring glasses), ... more True 3D displays, whether generated by volume holography, merged stereopsis (requiring glasses), or autostereoscopic methods (stereopsis without the need for special glasses), are useful in a great number of applications, ranging from training through product visualization to computer gaming. Holography provides an excellent 3D image but cannot yet be produced in real time, merged stereopsis results in accommodation-convergence conflict (where distance cues generated by the 3D appearance of the image conflict with those obtained from the angular position of the eyes) and lacks parallax cues, and autostereoscopy produces a 3D image visible only from a small region of space. Physical Optics Corporation is developing the next step in real-time 3D displays, the automultiscopic system, which eliminates accommodation-convergence conflict, produces 3D imagery from any position around the display, and includes true image parallax. Theory of automultiscopic display systems is presented, together with results from our prototype display, which produces 3D video imagery with full parallax cues from any viewing direction.

Advanced Materials Research, 2012

Sorting appears the most attention among all computational tasks over the past years because sort... more Sorting appears the most attention among all computational tasks over the past years because sorted data is at the heart of many computations. Sorting is of additional importance to parallel computing because of its close relation to the task of routing data among processes, which is an essential part of many parallel algorithms. Many parallel sorting algorithms have been investigated for a variety of parallel computer architectures. In this paper, three parallel sorting algorithms have been implemented and compared in terms of their overall execution time. The algorithms implemented are the odd-even transposition sort, parallel merge sort and parallel shell sort. Cluster of Workstations or Windows Compute Cluster has been used to compare the algorithms implemented. The C# programming language is used to develop the sorting algorithms. The MPI library has been selected to establish the communication and synchronization between processors. The time complexity for each parallel sortin...

Metallomics, 2013

Formation of non-native disulfide bonds within or between proteins can lead to protein misfolding... more Formation of non-native disulfide bonds within or between proteins can lead to protein misfolding and disruption to cellular metabolism. Such a process is defined as disulfide stress. A marked effect of disulfide stress in cells is the elevated accumulation of the intracellular aluminium ion (Al(3+)) accompanied by increased cytotoxicity. To gain an in-depth understanding of the underlying molecular mechanism for disulfide stress-induced aluminium toxicity, the complete set of Saccharomyces cerevisiae deletion mutants (5047) was screened in this study simultaneously with a combination of the two stressors, diamide and Al(3+). The combined treatment of a benign concentration of diamide (0.8 mM) with a sublethal concentration of aluminium sulfate (0.4 mM) revealed 494 sensitive deletion mutants, distinct from those found when either of the single stressors (0.8 mM diamide or 0.4 mM aluminium sulfate) was used. Hierarchical clustering and functional analyses of the 494 mutants sensitive to the dual stressors indicated a significant enrichment in the genes involved in cell wall homeostasis, signaling cascades, secretory transport machinery and detoxification. The results highlight the process of maintaining cell wall integrity as the central response to the combined exposure of diamide and Al(3+), which is mediated by the signaling pathways and transcription activation via Rlm1p and Swi6p for biosynthesis of the essential cell wall components such as glucan and chitin. Sensitivity of mutants associated with endoplasmic reticulum (ER), vesicle and vacuole functions demonstrates that secretory machinery is essential for surviving the stress conditions, probably due to their roles in transporting polysaccharides to the cell wall and detoxification of accumulated Al(3+). Finally, the phenotype of 100 previously uncharacterized genes against the dual stressors will contribute to their eventual functional annotation.