Exploring the Influence of Solvents on Electrochemically Etched Porous Silicon Based on Photoluminescence and Surface Morphology Analysis

Porous silicon (PSi) has promising applications in optoelectronic devices due to its efficient photoluminescence (PL). This study systematically investigates the effects of various organic solvents and their concentrations during electrochemical etching on the resulting PL and surface morphology of PSi. Ethanol, n-butanol, ethylene glycol (EG) and N,N-dimethylformamide (DMF) were employed as solvents in hydrofluoric acid (HF)-based silicon etching. The PL peak position exhibited progressive blue-shifting with increasing ethanol and EG concentrations, accompanied by reductions in the secondary peak intensity and emission linewidth. Comparatively, changes in n-butanol concentration only slightly impacted the main PL peak position. Additionally, distinct morphological transitions were observed for different solvents, with ethanol and n-butanol facilitating uniform single-layer porous structures at higher concentrations in contrast to the excessive etching caused by EG and DMF resulting in PL quenching. These results highlight the complex interdependencies between solvent parameters such as polarity, volatility and viscosity in modulating PSi properties through their influence on surface wetting, diffusion and etching kinetics. The findings provide meaningful guidelines for selecting suitable solvent conditions to tune PSi characteristics for optimized device performance.

Contribution of Accessibility to Urban Resilience and Evacuation Planning Using Spatial Analysis

Cities evolve and change with economic development and population growth, and urban planning laws in Taiwan have regulations that should be comprehensively reviewed every six years. Most current government policies aim to add new disaster prevention shelters or rescue stations. An economical way to improve the disaster prevention capabilities of urban planning is through examining or reviewing spatial structures and disaster prevention plans from the perspective of citizens or residents. The UN Office of Disaster Risk Reduction (UNDRR) launched the Making Cities Resilient Campaign policy to enhance disaster-resistant and sustainable urban environments through integrated disaster mitigation, reduction, response, and evacuation plans. This study used space syntax to ascertain evacuation route features using geometric distance analysis. There was 31.61% efficiency in relation to accessible roads on a comprehensive map. We could clearly see that since the areas in the first quadrant were relatively close to accessible roads, and there was an area that was not connected to the existing evacuation channels. The increased number of channels was more accessible and extensive. Such suggestions are helpful for government departments to prepare for disaster management. The spatial characteristics of the physical environment are explained by the accessibility and efficiency of axial maps and visibility analyzed by space syntax. Our findings reveal that space syntax is an important application when examining evacuation maps.

Mechanistic and compositional studies of the autophagy-inducing areca nut ingredient

Background/purpose

We previously found that the partially purified 30–100 kDa fraction of areca-nut-extract (ANE 30–100K) induces autophagy in different types of cells including oral carcinoma OECM-1 cells. This study was to analyze the composition and possible mechanisms of ANE 30-100K-induced autophagy (AIA).

Materials and methods

Phenol-sulfuric acid method and high performance anion exchange chromatography were utilized to analyze the composition of ANE 30–100K. OECM-1 and esophageal CE81T/VGH cells were taken as the experimental models. Microscope and transmission electron microscope were used to observe morphological changes. Cell viability and specific proteins were respectively measured by XTT and Western bot assay. shRNA and chemical inhibitors were applied to assess the involvement of Atg5, caveolin, and proteasome in AIA.

Results

ANE 30–100K contains ∼67% carbohydrate, which is composed of fucose (5.938%), arabinose (24.631%), glucosamine (8.066%), galactose (26.820%), glucose (21.388%), and mannose (13.157%). After ANE 30–100K stimulation, CE81T/VGH cells showed intracellular vacuoles, acidic vesicles, double-membrane vacuoles, and elevated LC3-II level. ANE 30-100K-induced cytotoxicity and LC3-II accumulation were significantly inhibited by Atg5 knockdown. Furthermore, the endocytosis inhibitor (methyl-β-cyclodextrin) and two caveolin shRNAs, as well as two proteasome inhibitors (lactacystin and epoxomicin), were shown to significantly attenuate ANE 30-100K-induced cytotoxicity and LC3-II accumulation in both OECM-1 and CE81T/VGH cells.

Conclusion

The major components of ANE 30–100K are carbohydrates. CE81T/VGH also exhibited autophagic responses to ANE 30–100K. Caveolin-mediated endocytosis and proteasome are involved in AIA. This study may have provided new knowledges of the action mechanisms and compositions of ANE 30–100K.

Experimental Assessment of the Fire Resistance Mechanisms of Timber-Steel Composites

Hybrid structures known as timber-steel composites (TSCs) have been extensively studied due to their potential use as alternative construction materials that can satisfy demands related to sustainability. In addition to load capacity, fire resistance is a major consideration regarding the extensive use of TSCs. In this study, 12 specimens were tested using a glulam timber material covering cold-formed steel at the center. Specifically, the TSCs were fabricated from two timber blocks and an I-shaped steel core assembled using dowels or glue as a major structure. In order to use additional timber as a fire protection layer to protect a major structure by its charcoal produced after being burned, an additional timber with 5 cm in thickness was used to cover the major structure. The 1-h fire testing of TSC following the ISO 834-1 standard was applied, in order to achieve the potential application for a 4-story timber building. The results showed that temperatures at the steel flange increased by more than 300 °C for the final 5 min in 10 out of the 12 TSC specimens, indicating that the fire protection provided by the timber structure was not sufficient. The charcoal layer surpassing the extra timber was originally set and entered the steel structure of the TSC, which was expected to retain its physical qualities after a fire. Methods for evaluating the charring properties, based on the conventional method for wood and the standard specification set by Eurocode 5, were used to assess the structural degradation of TSCs. The conventional assessments showed a divergence from the actual performance of TSCs. Such variations demonstrated the limitations of models for conventional wood in assessing the structure of a TSC. A realistic assessment was conducted to expand knowledge related to this composite under destructive processes and provide fire reference values for the practical implementation of TSCs.

Tocolysis and the risk of nonreassuring fetal status among pregnant women in labor: Findings from a population-based retrospective cohort study

The purpose of this study was to evaluate the association between tocolysis for preterm uterine contraction and the risk of nonreassuring fetal status.This was a retrospective cohort study using data from the Taiwan National Health Insurance Research Database. Pregnant women were enrolled if they delivered a baby during January 1, 2003 to December 31, 2011. The occurrence of the nonreassuring fetal status was compared between pregnant women with and without tocolytic treatment for preterm uterine contraction. Multivariable logistic regression models with adjusted cofounders were used to evaluate the association between tocolysis and the risk of nonreassuring fetal status.Of 24,133 pregnant women, 1115 (4.6%) received tocolytic treatment during pregnancy. After adjusting for covariates, pregnant women receiving tocolysis more than one time during pregnancy were found to have significantly higher risk of the nonreassuring fetal status when compared with pregnant women who did not receive tocolysis for uterine contraction (Odds Ratio = 2.70, 95% Confidence Interval: 1.13-6.49).Pregnant women with more frequent tocolysis for preterm uterine contraction during pregnancy had an increased risk of nonreassuring fetal status. Close evaluation of dose and duration of tocolytic treatment is necessary for pregnant women with preterm uterine contraction.

Association between Anticholinergic Medication Use and Risk of Dementia among Patients with Parkinson's Disease

STUDY OBJECTIVES

To evaluate the association between anticholinergic medication use, categorized by anticholinergic cognitive burden (primary objective) and cumulative dose (secondary objective), and the risk of developing dementia among patients with Parkinson's disease.

DESIGN

Retrospective cohort study with an active comparator design.

DATA SOURCE

National Health Insurance Research Database in Taiwan (2001-2011).

PATIENTS

A total of 1232 adults with Parkinson's disease who were diagnosed between 2002 and 2004 and taking at least one antiparkinson medication during this period were included. Of these patients, 694 were exposed to anticholinergic medications categorized as mild (reference group), and 538 were exposed to anticholinergic medications categorized as moderate or severe (exposure group).

MEASUREMENTS AND MAIN RESULTS

Exposure to different types of anticholinergic medications was categorized by using the Anticholinergic Cognitive Burden (ACB) scale, and cumulative doses of anticholinergic medications were measured by using the cumulative minimum doses (cMD) method. Associations between anticholinergic medication use and risk of dementia were assessed by multivariable Cox proportional hazards models. The type of anticholinergics used (moderate or severe vs mild ACB) was not significantly associated with an increased risk of developing dementia (hazard ratio [HR] 0.97, 95% confidence interval [CI] 0.72-1.27). After adjusting for confounders, a high cumulative dose of anticholinergic drug (> 1095 cumulative minimum doses [cMDs]) was found to be significantly associated with an increased risk of developing dementia when compared with a low cumulative dose of anticholinergic drug (≤ 90 cMDs) (HR 3.06, 95% CI 1.35-6.97).

CONCLUSION

Among patients with Parkinson's disease in Taiwan, those with a high cumulative dose of anticholinergics had an increased risk of being diagnosed with dementia. Physicians should consider prescribing the lowest therapeutic dose of anticholinergic medication when making treatment decisions for patients with Parkinson's disease.

Hollow Few-Layer Graphene-Based Structures from Parafilm Waste for Flexible Transparent Supercapacitors and Oil Spill Cleanup

We report a versatile strategy to exploit parafilm waste as a carbon precursor for fabrication of freestanding, hollow few-layer graphene fiber mesh (HFGM) structures without use of any gaseous carriers/promoters via an annealing route. The freestanding HFGMs possess good mechanical flexibility, tailorable transparency, and high electrical conductivity, consequently qualifying them as promising electrochemical electrodes. Because of the hollow spaces, electrolyte ions can easily access into and contact with interior surfaces of the graphene fibers, accordingly increasing electrode/electrolyte interfacial area. As expected, solid-state supercapacitors based on the HFGMs exhibit a considerable enhancement in specific capacitance (20-30 fold) as compared to those employing chemical vapor deposition compact graphene films. Moreover, the parafilm waste is found to be beneficial for one-step fabrication of nanocarbon/few-layer graphene composite meshes with superior electrochemical performance, outstanding superhydrophobic property, good self-cleaning ability, and great promise for oil spill cleanup.

The association between comorbid anxiety disorders and the risk of stroke among patients with diabetes: An 11-year population-based retrospective cohort study

BACKGROUND

Diabetes and anxiety disorders are independent risk factors for stroke. However, it remains unclear whether the risk of stroke is higher among diabetic patients with comorbid anxiety than without comorbid anxiety. Therefore, the purpose of this study was to investigate the association between comorbid anxiety and the risk of stroke among patients with diabetes.

METHODS

This is a retrospective cohort study. We used the National Health Insurance Research Database in Taiwan to identify a diabetes cohort with a new diagnosis of an anxiety disorder but without a history of stroke. The enrollment period was 2001-2006 with up to 11 years of follow-up data. Comorbid anxiety was defined by both a clinical diagnosis of the DSM-IV (ICD-9-CM) and prescriptions for anxiolytic medications. Propensity score matching was performed to balance the selected confounders between the anxiety-exposed group and anxiety non-exposed group. Cox-propositional hazard regression models were used to evaluate the association between comorbid anxiety and the risk of stroke.

RESULTS

Among patients with diabetes (N=40,846), an estimated 5.8% (N=2374) of patients had comorbid anxiety disorders. Diabetic patients with comorbid anxiety were significantly associated with a higher risk of stroke compared to patients without comorbid anxiety (hazard ratio: 1.33, 95% confidence interval: 1.02-1.72).

LIMITATIONS

The severity of anxiety or diabetes could not be measured from the claims data. Residual confounding may still exist.

CONCLUSION

A significantly elevated risk of stroke was observed in association with comorbid anxiety among patients with diabetes. Psychiatrists should consider routine screening for anxiety disorders to prevent a stroke event among patients with diabetes.

Bacterial community composition in Brazilian Anthrosols and adjacent soils characterized using culturing and molecular identification

Microbial community composition was examined in two soil types, Anthrosols and adjacent soils, sampled from three locations in the Brazilian Amazon. The Anthrosols, also known as Amazonian dark earths, are highly fertile soils that are a legacy of pre-Columbian settlement. Both Anthrosols and adjacent soils are derived from the same parent material and subject to the same environmental conditions, including rainfall and temperature; however, the Anthrosols contain high levels of charcoal-like black carbon from which they derive their dark color. The Anthrosols typically have higher cation exchange capacity, higher pH, and higher phosphorus and calcium contents. We used culture media prepared from soil extracts to isolate bacteria unique to the two soil types and then sequenced their 16S rRNA genes to determine their phylogenetic placement. Higher numbers of culturable bacteria, by over two orders of magnitude at the deepest sampling depths, were counted in the Anthrosols. Sequences of bacteria isolated on soil extract media yielded five possible new bacterial families. Also, a higher number of families in the bacteria were represented by isolates from the deeper soil depths in the Anthrosols. Higher bacterial populations and a greater diversity of isolates were found in all of the Anthrosols, to a depth of up to 1 m, compared to adjacent soils located within 50-500 m of their associated Anthrosols. Compared to standard culture media, soil extract media revealed diverse soil microbial populations adapted to the unique biochemistry and physiological ecology of these Anthrosols.

Mutation analysis of the human NR4A2 gene, an essential gene for midbrain dopaminergic neurogenesis, in schizophrenic patients

Recent studies have revealed that an orphan receptor gene of the steroid/thyroid hormone nuclear receptor superfamily, the Nurr1 gene, is essential for the neurogenesis and differentiation of dopaminergic neurons in the midbrain of mice. Transgenic mice lacking the Nurr1 gene soon die after birth and are devoid of dopaminergic neurons in the midbrain. Heterozygous mice survive postnatally without obvious locomotor deficits; however, they have increased vulnerability to dopaminergic neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). In view of the importance of dopamine neurotransmission in brain function, we were interested to know if the human homologous gene of murine Nurr1, the NR4A2 gene, may play a role in the pathogenesis of schizophrenia. We systematically sequenced all the exons of the human NR4A2 gene to search for molecular variants in a cohort of Chinese schizophrenic patients from Taiwan. Two molecular variants were identified: a G-insertion in intron 6 (designated IVS6 + 17 [see text] + 18insG), and a G-deletion in the untranslated exon 1 (designated c.-469delG). The IVS6 + 17 [see text] + 18insG is a polymorphic one; further case control study, however, did not reveal association of this polymorphism with schizophrenia. The c.-469delG is a rare variant found in two unrelated patients among 177 schizophrenic patients, but not in 130 nonpsychotic controls. The result suggests that the c.-469delG and possibly other variants of the NR4A2 gene may be of relevance to the complex factors involved in the pathogenesis of schizophrenia.

Mutation analysis of the human NR4A2 gene, an essential gene for midbrain dopaminergic neurogenesis, in schizophrenic patients

Recent studies have revealed that an orphan receptor gene of the steroid/thyroid hormone nuclear receptor superfamily, the Nurr1 gene, is essential for the neurogenesis and differentiation of dopaminergic neurons in the midbrain of mice. Transgenic mice lacking the Nurr1 gene soon die after birth and are devoid of dopaminergic neurons in the midbrain. Heterozygous mice survive postnatally without obvious locomotor deficits; however, they have increased vulnerability to dopaminergic neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). In view of the importance of dopamine neurotransmission in brain function, we were interested to know if the human homologous gene of murine Nurr1, the NR4A2 gene, may play a role in the pathogenesis of schizophrenia. We systematically sequenced all the exons of the human NR4A2 gene to search for molecular variants in a cohort of Chinese schizophrenic patients from Taiwan. Two molecular variants were identified: a G-insertion in intron 6 (designated IVS6 + 17 [see text] + 18insG), and a G-deletion in the untranslated exon 1 (designated c.-469delG). The IVS6 + 17 [see text] + 18insG is a polymorphic one; further case control study, however, did not reveal association of this polymorphism with schizophrenia. The c.-469delG is a rare variant found in two unrelated patients among 177 schizophrenic patients, but not in 130 nonpsychotic controls. The result suggests that the c.-469delG and possibly other variants of the NR4A2 gene may be of relevance to the complex factors involved in the pathogenesis of schizophrenia.

Mutation analysis of the human NR4A2 gene, an essential gene for midbrain dopaminergic neurogenesis, in schizophrenic patients

Recent studies have revealed that an orphan receptor gene of the steroid/thyroid hormone nuclear receptor superfamily, the Nurr1 gene, is essential for the neurogenesis and differentiation of dopaminergic neurons in the midbrain of mice. Transgenic mice lacking the Nurr1 gene soon die after birth and are devoid of dopaminergic neurons in the midbrain. Heterozygous mice survive postnatally without obvious locomotor deficits; however, they have increased vulnerability to dopaminergic neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). In view of the importance of dopamine neurotransmission in brain function, we were interested to know if the human homologous gene of murine Nurr1, the NR4A2 gene, may play a role in the pathogenesis of schizophrenia. We systematically sequenced all the exons of the human NR4A2 gene to search for molecular variants in a cohort of Chinese schizophrenic patients from Taiwan. Two molecular variants were identified: a G-insertion in intron 6 (designated IVS6 + 17 [see text] + 18insG), and a G-deletion in the untranslated exon 1 (designated c.-469delG). The IVS6 + 17 [see text] + 18insG is a polymorphic one; further case control study, however, did not reveal association of this polymorphism with schizophrenia. The c.-469delG is a rare variant found in two unrelated patients among 177 schizophrenic patients, but not in 130 nonpsychotic controls. The result suggests that the c.-469delG and possibly other variants of the NR4A2 gene may be of relevance to the complex factors involved in the pathogenesis of schizophrenia.

Systematic search for mutations in the human tissue inhibitor of metalloproteinases-3 (TIMP-3) gene on chromosome 22 and association study with schizophrenia

Several linkage studies have suggested that chromosome 22q12-q13 is a putative region for schizophrenic genes. In this study, the human tissue inhibitor of metalloproteinase-3 (TIMP-3) gene was investigated as positional candidate gene for schizophrenia because of its regulatory function on extracellular matrix proteins, cell adhesion molecules, and neural cell adhesion molecules in the brain. We systematically searched for the nucleotide variants by sequencing all the exons and their flanking intronic sequences in a sample of Chinese schizophrenic patients from Taiwan. Two silent mutations in the exon 3 were identified: c.249T-->C at codon 83 (His) and c.261C-->T at codon 87 (Ser). However, no mutations causing amino acid alteration or aberrant splicing of transcripts were observed. Hence, it is unlikely that the TIMP-3 gene itself may play an important role in the genetic susceptibility to schizophrenia. Further case control association study revealed a significant difference of genotype distribution of the c.249T-->C between schizophrenic patients and control. This finding supports that 22q12 is a schizophrenia susceptible region, and it is likely that there might be other genetic mutations in the neighborhood of the TIMP-3 gene locus that may contribute to the susceptibility of schizophrenia.

Lack of evidence to support the association of the human prion gene with schizophrenia

Recently a new variant of Creutzfeldt-Jakob disease, a human prion disease, with prominent psychiatric manifestations in the early stage was identified, suggesting that human prion disease may be associated with mental disorders. Furthermore, a novel missense mutation with asparagine-to-serine substitution at codon 171 of the human prion gene (N171S) was identified in a family with severe psychiatric symptoms. This finding provides further clue that the prion gene may be a susceptibility gene for certain psychiatric disorders. We systematically sequenced the protein-coding and untranslated exons of prion gene in 62 Han Chinese schizophrenic patients with positive family history from Taiwan. We identified two polymorphisms that alter amino acid sequences, a methionine/valine at codon 129 (M129V) and a glutamate/lysine at codon 219 (E219K), respectively. Further comparison of the genotype, allele and haplotype frequency distributions of these two polymorphisms between 234 schizophrenic patients and 100 non-psychotic controls, however, did not reveal significant differences between two groups. Besides, no other mutations in the prion gene were identified in these 62 patients. Hence, our results suggest that the prion gene may not play a major role in conferring susceptibility to schizophrenia.

Alteration in the expression of protein kinase C isoforms in human hepatocellular carcinoma

This study was designed to investigate the alterations of individual protein kinase C (PKC) isoforms in human liver cancer. Surgical specimens of hepatocellular carcinoma and adjacent normal tissues were extracted into cytosolic and membranous fractions. The level of membrane-bound PKCalpha in the cancer tissue was significantly lower than that in the adjacent normal tissue and consistent with the change in PKC activity. In addition, there was a significant negative correlation between PKCalpha and tumor size. In both cytosolic and membrane fractions, levels of PKCdelta and PKCzeta was significantly higher in the cancer tissue than those in the adjacent normal liver tissue. The alterations in the PKC isoforms signify their roles in the hyperproliferation in liver cancer.

Detection of Borna disease virus RNA from peripheral blood cells in schizophrenic patients and mental health workers

Accumulating evidence suggests that Borna disease virus (BDV), a neurotropic, negative-stranded RNA virus, might be associated with certain human mental disorders. Several research groups reported that psychiatric patients had a significantly higher prevalence of BDV serum antibodies than normal controls. In addition, a significantly higher presence of BDV RNA from peripheral blood cells was identified in mental patients than in controls. In our previous study, we first identified the presence of BDV serum antibodies in a cohort of Chinese schizophrenic patients from Taiwan, and we also demonstrated a significantly higher seroprevalence of BDV antibodies among schizophrenic patients than in non-psychiatric controls. Prompted by the positive seroepidemiological result, we set out to investigate the detection of BDV RNA from the peripheral blood cells of our schizophrenic patients. By using the reverse transcription-polymerase chain reaction (RT-PCR) method, 10 out of 74 Chinese schizophrenic patients from Taiwan were found to have BDV RNA in their blood cells, whereas only one out of 69 controls was positive. The BDV RNA detection rate among schizophrenic patients was significantly higher than that in controls (14% vs 1.4%, P < 0.01). Furthermore, we studied the BDV RNA detection rate among mental health workers, and seven out of 45 mental health workers were found to have positive results. The prevalence rate was significantly higher than that in normal controls (15% vs 1.4%, P < 0.001), which lends further support to our previous finding that mental health workers have a significantly higher presence of BDV serum antibodies. In summary, our data support the finding that BDV infection might be a contributory factor to the pathogenesis of schizophrenia in the Chinese population.

Genetic association study of a polymorphic CAG repeats array of calcium-activated potassium channel (KCNN3) gene and schizophrenia among the Chinese population from Taiwan

Chandy et al suggested that a novel human neuronal small conductance, calcium-activated potassium channel gene, KCNN3, might be a candidate for schizophrenia. The KCNN3 cDNA sequences contain two stretches of CAG trinucleotide repeats encoding two separate polyglutamine segments near the N-terminus of this channel protein. The second CAG repeat was found to be highly polymorphic in the Caucasian population from both Europe and USA. Upon comparing the allelic frequency distribution between schizophrenic patients and ethnically matched controls, a significant excess of longer CAG repeats in schizophrenic patients was observed. A similar result was obtained in a recent replication study by Bowen et al, performed in Caucasians from UK or Eire. These results suggest an association between the longer CAG repeat allele of the KCNN3 gene and schizophrenia susceptibility. To verify if similar results can be observed in the Chinese population, we carried out a case-control study to compare the allelic frequency distribution of the CAG repeat of the KCNN3 gene between 92 Chinese schizophrenic patients and 100 normal controls from Taiwan. No significant difference of the allelic frequency distribution of the second CAG repeats was detected between the two groups (Wilcoxon Rank Sum test, P = 0.664). In addition, no over-representation of CAG repeats longer than the mode (19 repeats) was found in the patients' group (Fisher's exact test, P = 0.739). Thus, our data do not support that the second polymorphic CAG repeat of the KCNN3 gene may have an association with schizophrenia in our population.

The effect of pentoxifylline on cochlear blood flow

Pentoxifylline, a phosphodiesterase inhibitor and hemorrheologic agent has been found to increase oxygen delivery to ischemic tissue. Intravenous pentoxifylline was administered to normal guinea pigs in order to assess the effect of pentoxifylline on cochlear blood flow and to elucidate its mechanism of action. Intravenous pentoxifylline was found to acutely increase cochlear blood flow in a dose-dependent manner. In normal animals, the effect appeared strongly related to the rheologic properties of this agent rather than a vasodilative action. Normovolemic hemodilution with 75% dextran resulted in no increase in cochlear blood flow during infusion of pentoxifylline, whereas the application of nitroprusside over the round window failed to abolish the effect of pentoxifylline.