Jan van Stam - Academia.edu (original) (raw)

Papers by Jan van Stam

Research paper thumbnail of Effects on ink setting in flexographic printing: Coating polarity and dot gain

Nordic Pulp and Paper Research Journal

Research paper thumbnail of 2-Naphthol Complexation by �-Cyclodextrin:� Influence of Added Short Linear Alcohols

The Journal of Physical Chemistry, 1996

Research paper thumbnail of Abstract W P318: Declining Mortality in Cerebral Venous Thrombosis: A Systematic Review

Research paper thumbnail of Normal and anomalous diffusion

Research paper thumbnail of Tuning of the α‐Terthiophene Radical Cation Coupling Reaction Using Mixed Micelles with Varying Charge Density

Chemphyschem, Nov 11, 2005

ABSTRACT The photophysics and photochemistry of alpha-terthiophene (alphaT), compartmentalized in... more ABSTRACT The photophysics and photochemistry of alpha-terthiophene (alphaT), compartmentalized in mixed nonionic/anionic micelles, have been investigated with focus on the influence of the micellar surface charge density on the formation of the radical coupling product alpha-hexathiophene (alphaH). By varying the ratio of nonionic-to-anionic surfactants, and assuming ideal mixing, the charge density of the mixed micelles was varied. From Poisson-Boltzmann calculations, performed using the cell model, the electrostatic potential and the counterion activity were estimated as a function of the distance from the micellar surface. Upon excitation, the triplet state of alphaT is formed, from which the alphaT radical cation can be formed by absorption of a second photon. The radical cation can form alphaH if it encounters another alphaT radical cation. Under the experimental conditions used, this implies that the alphaH formation only occurs if the compartmentalized radical cation is able to migrate from its host micelle to another micelle, either via the surrounding bulk or by fusion of two micelles followed by mixing of their contents before micellar fission. The formation yield of the radical cation depends on the charge density of the mixed micelle; a lower charge density, that is, an increased amount of nonionic surfactant, lowers the yield. The yield of the coupling product alphaH, however, does not follow the same trend. A maximum yield of alphaH is found at intermediate nonionic surfactant molar ratios. This behavior is understood in terms of the Poisson-Boltzmann simulation results and by comparing charge-density changes as a function of molar fraction with the changes in counterion activity. The alphaH yield is a result of the balance between an increased possibility of radical cation bulk migration and a lowered electrostatic stabilization of the radical.

Research paper thumbnail of Fluorescence microscopy – the most versatile tool for in situ investigation of colloids?

Research paper thumbnail of Bimolecular Processes of a-Terthiophene in a �-Cyclodextrin Environment:� An Exploratory Study

The Journal of Physical Chemistry, 1996

Research paper thumbnail of Effects of elevated temperature on flexographic printing

Research paper thumbnail of a-Terthiophene in non-ionic Triton X-100 micelles: biphotonic creation of its radical cation

Research paper thumbnail of High Diagnostic Yield and Accuracy of History, Physical Examination, and ECG in Patients with Transient Loss of Consciousness in FAST: The Fainting Assessment Study

J Cardiovasc Electrophysiol, 2007

Transient loss of consciousness (TLOC) is a common clinical problem. The aim of this study was to... more Transient loss of consciousness (TLOC) is a common clinical problem. The aim of this study was to assess the yield and accuracy of the initial evaluation, consisting of standardized history, physical examination, and ECG performed by attending physicians in patients with TLOC. Five hundred and three adult patients (mean age 53 +/- 19; 56% male) presenting with TLOC to the Academic Medical Center Amsterdam between February 2000 and May 2002 were included in this study. After initial evaluation, the physician made a certain, a highly likely (>80% certain), or no initial diagnosis. Initially undiagnosed patients received additional cardiological testing, additional history taking, and autonomic function tests. After 2 years of follow-up, an expert committee determined the final diagnoses. Two-year follow-up was obtained in 99% of the patients. The yield of certain diagnoses after the initial evaluation was 24%, increasing to 63% after including the highly likely diagnoses. The diagnostic accuracy of the initial certain diagnoses was 93% (95% CI 87-97%), decreasing to 88% (95% CI 84-91%) after inclusion of the initial highly likely diagnoses. Attending physicians can make a diagnosis based on initial evaluation in 63% of patients with TLOC, with an overall diagnostic accuracy of 88%. The use of additional testing, beyond history, physical examination, and ECG can be avoided in many patients with TLOC.

Research paper thumbnail of Latex particle behavior studied in the wet state with fluorescence microscopy

Research paper thumbnail of Anticoagulation for cerebral sinus thrombosis

Research paper thumbnail of Observation of a-terthiophene excited dimer fluorescence in aqueous solutions of ?-cyclodextrin

Research paper thumbnail of Abstract W P145: Shift in Sex Ratio Over Time in Cerebral Venous Thrombosis

Research paper thumbnail of Imbibition into Model Calcium Carbonate Coatings of Fluids with Different Dipole Moments

Appita Journal 2006 59 471 485, 2006

Research paper thumbnail of Global compartmental analysis of the fluorescence decay surface of intramolecular chain mediated and through space excited-state complex formation of a silane linked donor-acceptor system

Research paper thumbnail of Early Seizures in Cerebral Vein and Dural Sinus Thrombosis

ABSTRACT The risk of seizure early after the diagnosis of cerebral vein and dural sinus thrombosi... more ABSTRACT The risk of seizure early after the diagnosis of cerebral vein and dural sinus thrombosis (CVT) is not known, and the use of prophylactic antiepileptic (AED) medication in the acute phase of CVT is controversial. In a multicenter, prospective, observational study, we analyzed the risk factors for seizures experienced before the diagnosis of CVT was confirmed (presenting seizures) or within the following 2 weeks (early seizures). The risk of occurrence of early seizures was compared in 4 risk strata and related to whether patients received AEDs or not. Criteria for the strata were "presenting seizures" and "supratentorial lesions." Two hundred forty-five of 624 (39.3%) patients with CVT experienced presenting seizures, and 43 (6.9%) patients had early seizure. In logistic-regression analysis, supratentorial lesion (odds ratio [OR]=4.05, 95% CI=2.74 to 5.95), cortical vein thrombosis (OR=2.31, 95% CI=1.44 to 3.73), sagittal sinus thrombosis (OR=2.18, 95% CI=1.50 to 3.18), and puerperal CVT (OR=2.06, 95% CI=1.19 to 3.55) were associated with presenting seizures, whereas supratentorial lesion (OR=3.09, 95% CI=1.56 to 9.62) and presenting seizures (OR=1.74, 95% CI=0.90 to 3.37) predicted early seizures. The risk of early seizures in patients with supratentorial lesions and presenting seizures was significantly lower when AED prophylaxis was used (1 with seizures in 148 patients with AEDs vs 25 in 47 patients without AEDs; OR=0.006, 95% CI=0.001 to 0.05). CVT patients with supratentorial lesions had a higher risk for both presenting and early seizures, whereas patients with presenting seizures had a higher risk of recurrent seizures within 2 weeks. Our results support the prescription of AEDs in acute CVT patients with supratentorial lesions who present with seizures.

Research paper thumbnail of Effects of ink setting in flexographic printing: Coating polarity and dot gain

Nordic Pulp and Paper Research Journal

Research paper thumbnail of Mechanical thrombectomy in cerebral venous thrombosis: systematic review of 185 cases

Stroke; a journal of cerebral circulation, 2015

Cerebral venous thrombosis is generally treated with anticoagulation. However, some patients do n... more Cerebral venous thrombosis is generally treated with anticoagulation. However, some patients do not respond to medical therapy and these might benefit from mechanical thrombectomy. The aim of this study was to gain a better understanding of the efficacy and safety of mechanical thrombectomy in patients with cerebral venous thrombosis, by performing a systematic review of the literature. We identified studies published between January 1995 and February 2014 from PubMed and Ovid. We included all cases of cerebral venous thrombosis in whom mechanical thrombectomy was performed with or without intrasinus thrombolysis. Good outcome was defined as normal or mild neurological deficits at discharge (modified Rankin Scale, 0-2). Secondary outcome variables included periprocedural complications and recanalization rates. Our study included 42 studies (185 patients). Sixty percent of patient had a pretreatment intracerebral hemorrhage and 47% were stuporous or comatose. AngioJet was the most co...

Research paper thumbnail of Fluorescence Spectroscopy Studies on Polymer Blend Solutions and Films for Photovoltaics

Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2015

ABSTRACT The polymer TQ1, (poly[2,3-bis-(3-octyloxyphenyl)quinoxaline-5,8-diyl-alt-thiophene-2,5-... more ABSTRACT The polymer TQ1, (poly[2,3-bis-(3-octyloxyphenyl)quinoxaline-5,8-diyl-alt-thiophene-2,5-diyl]) is a popular candidate as donor in organic solar cells. A suitable acceptor molecule together with TQ1 is [6,6]-phenyl-C71-butyric acid methyl ester (PC70BM).

Research paper thumbnail of Effects on ink setting in flexographic printing: Coating polarity and dot gain

Nordic Pulp and Paper Research Journal

Research paper thumbnail of 2-Naphthol Complexation by �-Cyclodextrin:� Influence of Added Short Linear Alcohols

The Journal of Physical Chemistry, 1996

Research paper thumbnail of Abstract W P318: Declining Mortality in Cerebral Venous Thrombosis: A Systematic Review

Research paper thumbnail of Normal and anomalous diffusion

Research paper thumbnail of Tuning of the α‐Terthiophene Radical Cation Coupling Reaction Using Mixed Micelles with Varying Charge Density

Chemphyschem, Nov 11, 2005

ABSTRACT The photophysics and photochemistry of alpha-terthiophene (alphaT), compartmentalized in... more ABSTRACT The photophysics and photochemistry of alpha-terthiophene (alphaT), compartmentalized in mixed nonionic/anionic micelles, have been investigated with focus on the influence of the micellar surface charge density on the formation of the radical coupling product alpha-hexathiophene (alphaH). By varying the ratio of nonionic-to-anionic surfactants, and assuming ideal mixing, the charge density of the mixed micelles was varied. From Poisson-Boltzmann calculations, performed using the cell model, the electrostatic potential and the counterion activity were estimated as a function of the distance from the micellar surface. Upon excitation, the triplet state of alphaT is formed, from which the alphaT radical cation can be formed by absorption of a second photon. The radical cation can form alphaH if it encounters another alphaT radical cation. Under the experimental conditions used, this implies that the alphaH formation only occurs if the compartmentalized radical cation is able to migrate from its host micelle to another micelle, either via the surrounding bulk or by fusion of two micelles followed by mixing of their contents before micellar fission. The formation yield of the radical cation depends on the charge density of the mixed micelle; a lower charge density, that is, an increased amount of nonionic surfactant, lowers the yield. The yield of the coupling product alphaH, however, does not follow the same trend. A maximum yield of alphaH is found at intermediate nonionic surfactant molar ratios. This behavior is understood in terms of the Poisson-Boltzmann simulation results and by comparing charge-density changes as a function of molar fraction with the changes in counterion activity. The alphaH yield is a result of the balance between an increased possibility of radical cation bulk migration and a lowered electrostatic stabilization of the radical.

Research paper thumbnail of Fluorescence microscopy – the most versatile tool for in situ investigation of colloids?

Research paper thumbnail of Bimolecular Processes of a-Terthiophene in a �-Cyclodextrin Environment:� An Exploratory Study

The Journal of Physical Chemistry, 1996

Research paper thumbnail of Effects of elevated temperature on flexographic printing

Research paper thumbnail of a-Terthiophene in non-ionic Triton X-100 micelles: biphotonic creation of its radical cation

Research paper thumbnail of High Diagnostic Yield and Accuracy of History, Physical Examination, and ECG in Patients with Transient Loss of Consciousness in FAST: The Fainting Assessment Study

J Cardiovasc Electrophysiol, 2007

Transient loss of consciousness (TLOC) is a common clinical problem. The aim of this study was to... more Transient loss of consciousness (TLOC) is a common clinical problem. The aim of this study was to assess the yield and accuracy of the initial evaluation, consisting of standardized history, physical examination, and ECG performed by attending physicians in patients with TLOC. Five hundred and three adult patients (mean age 53 +/- 19; 56% male) presenting with TLOC to the Academic Medical Center Amsterdam between February 2000 and May 2002 were included in this study. After initial evaluation, the physician made a certain, a highly likely (>80% certain), or no initial diagnosis. Initially undiagnosed patients received additional cardiological testing, additional history taking, and autonomic function tests. After 2 years of follow-up, an expert committee determined the final diagnoses. Two-year follow-up was obtained in 99% of the patients. The yield of certain diagnoses after the initial evaluation was 24%, increasing to 63% after including the highly likely diagnoses. The diagnostic accuracy of the initial certain diagnoses was 93% (95% CI 87-97%), decreasing to 88% (95% CI 84-91%) after inclusion of the initial highly likely diagnoses. Attending physicians can make a diagnosis based on initial evaluation in 63% of patients with TLOC, with an overall diagnostic accuracy of 88%. The use of additional testing, beyond history, physical examination, and ECG can be avoided in many patients with TLOC.

Research paper thumbnail of Latex particle behavior studied in the wet state with fluorescence microscopy

Research paper thumbnail of Anticoagulation for cerebral sinus thrombosis

Research paper thumbnail of Observation of a-terthiophene excited dimer fluorescence in aqueous solutions of ?-cyclodextrin

Research paper thumbnail of Abstract W P145: Shift in Sex Ratio Over Time in Cerebral Venous Thrombosis

Research paper thumbnail of Imbibition into Model Calcium Carbonate Coatings of Fluids with Different Dipole Moments

Appita Journal 2006 59 471 485, 2006

Research paper thumbnail of Global compartmental analysis of the fluorescence decay surface of intramolecular chain mediated and through space excited-state complex formation of a silane linked donor-acceptor system

Research paper thumbnail of Early Seizures in Cerebral Vein and Dural Sinus Thrombosis

ABSTRACT The risk of seizure early after the diagnosis of cerebral vein and dural sinus thrombosi... more ABSTRACT The risk of seizure early after the diagnosis of cerebral vein and dural sinus thrombosis (CVT) is not known, and the use of prophylactic antiepileptic (AED) medication in the acute phase of CVT is controversial. In a multicenter, prospective, observational study, we analyzed the risk factors for seizures experienced before the diagnosis of CVT was confirmed (presenting seizures) or within the following 2 weeks (early seizures). The risk of occurrence of early seizures was compared in 4 risk strata and related to whether patients received AEDs or not. Criteria for the strata were "presenting seizures" and "supratentorial lesions." Two hundred forty-five of 624 (39.3%) patients with CVT experienced presenting seizures, and 43 (6.9%) patients had early seizure. In logistic-regression analysis, supratentorial lesion (odds ratio [OR]=4.05, 95% CI=2.74 to 5.95), cortical vein thrombosis (OR=2.31, 95% CI=1.44 to 3.73), sagittal sinus thrombosis (OR=2.18, 95% CI=1.50 to 3.18), and puerperal CVT (OR=2.06, 95% CI=1.19 to 3.55) were associated with presenting seizures, whereas supratentorial lesion (OR=3.09, 95% CI=1.56 to 9.62) and presenting seizures (OR=1.74, 95% CI=0.90 to 3.37) predicted early seizures. The risk of early seizures in patients with supratentorial lesions and presenting seizures was significantly lower when AED prophylaxis was used (1 with seizures in 148 patients with AEDs vs 25 in 47 patients without AEDs; OR=0.006, 95% CI=0.001 to 0.05). CVT patients with supratentorial lesions had a higher risk for both presenting and early seizures, whereas patients with presenting seizures had a higher risk of recurrent seizures within 2 weeks. Our results support the prescription of AEDs in acute CVT patients with supratentorial lesions who present with seizures.

Research paper thumbnail of Effects of ink setting in flexographic printing: Coating polarity and dot gain

Nordic Pulp and Paper Research Journal

Research paper thumbnail of Mechanical thrombectomy in cerebral venous thrombosis: systematic review of 185 cases

Stroke; a journal of cerebral circulation, 2015

Cerebral venous thrombosis is generally treated with anticoagulation. However, some patients do n... more Cerebral venous thrombosis is generally treated with anticoagulation. However, some patients do not respond to medical therapy and these might benefit from mechanical thrombectomy. The aim of this study was to gain a better understanding of the efficacy and safety of mechanical thrombectomy in patients with cerebral venous thrombosis, by performing a systematic review of the literature. We identified studies published between January 1995 and February 2014 from PubMed and Ovid. We included all cases of cerebral venous thrombosis in whom mechanical thrombectomy was performed with or without intrasinus thrombolysis. Good outcome was defined as normal or mild neurological deficits at discharge (modified Rankin Scale, 0-2). Secondary outcome variables included periprocedural complications and recanalization rates. Our study included 42 studies (185 patients). Sixty percent of patient had a pretreatment intracerebral hemorrhage and 47% were stuporous or comatose. AngioJet was the most co...

Research paper thumbnail of Fluorescence Spectroscopy Studies on Polymer Blend Solutions and Films for Photovoltaics

Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2015

ABSTRACT The polymer TQ1, (poly[2,3-bis-(3-octyloxyphenyl)quinoxaline-5,8-diyl-alt-thiophene-2,5-... more ABSTRACT The polymer TQ1, (poly[2,3-bis-(3-octyloxyphenyl)quinoxaline-5,8-diyl-alt-thiophene-2,5-diyl]) is a popular candidate as donor in organic solar cells. A suitable acceptor molecule together with TQ1 is [6,6]-phenyl-C71-butyric acid methyl ester (PC70BM).