Violence Against Children, Self-Harm, and Suicidal Behaviors: A Pooled and Country-Specific Analysis of Eight Low- and Middle-Income Countries.

PURPOSE: This study assessed associations between experiences of physical or sexual violence in childhood and self-harm, suicidal ideation, and suicide attempts among young people in low- and middle-income countries (LMICs) and whether these associations varied by sex and perpetrator identity. METHODS: We used nationally representative data from the Violence Against Children and Youth Surveys in eight LMICs (2017-2019). The analytic sample included 33,381 young men and women (ages 13-24 years). Multivariable logistic regressions with country-fixed effects were used to estimate the associations between childhood physical and sexual violence and the three outcomes. Stratified analyses were performed by country, participant's sex, and type of perpetrator (parent/caregiver, other adults, peers, and intimate partner). RESULTS: About 40% of the participants reported physical childhood violence, and 10% experienced childhood sexual violence. Childhood violence was associated with increased odds of self-harm (physical violence: adjusted odds ratio [aOR]: 2.2, 95% confidence interval [CI]: 2.0-2.4; sexual violence: aOR: 2.7, 95%, CI: 2.3-3.0), suicidal ideation (physical: aOR: 3.0, 95% CI: 2.7-3.3; sexual: aOR: 4.0, 95%, CI: 3.6-4.5), and suicide attempts (physical: aOR: 3.6, 95% CI: 3.2-4.1; sexual: aOR: 4.9, 95%, CI: 4.3-5.7). Consistent findings were observed in country-specific analyses. The odds of all outcomes were highest among those who experienced childhood physical violence by intimate partners and childhood sexual violence by parents or caregivers. Young women who experienced childhood sexual violence had higher odds for all outcomes than young men. DISCUSSION: Violence prevention and mental health programs for young people in LMICs should consider the types of violence experienced, the perpetrator, and the sex of the survivor.

Problems accessing health care and under-5 mortality: a pooled analysis of 50 low- and middle-income countries.

BACKGROUND: Access to health care remains suboptimal in low- and middle-income countries (LMICs) and continues to hinder survival in early childhood. We systematically assessed the association between problems accessing health care (PAHC) and under-five mortality (U5M). METHODS: Child mortality data on 724 335 livebirths came from the latest Demographic and Health Surveys of 50 LMICs (2013-2021). Reasons for PAHC were classified into three domains: 'money needed for treatment' (economic), 'distance to health facility' (physical), 'getting permission' or 'not wanting to go alone' (socio-cultural). Multivariable logistic regression was used to estimate the association between PAHC (any and by each type) and U5M. RESULTS: In our pooled sample, 47.3 children per 1000 livebirths died before age of 5, and 57.1% reported having experienced PAHC (ranging from 45.3% in Europe & Central Asia to 72.7% in Latin America & Caribbean). Children with any PAHC had higher odds of U5M (OR: 1.05, 95% CI: 1.02, 1.09), and this association was especially significant in sub-Saharan Africa. Of different domains of PAHC, socio-cultural PAHC was found to be most significant. CONCLUSIONS: Access to health care in LMICs needs to be improved by expanding health care coverage, building health facilities, and focusing more on context-specific socio-cultural barriers.

Women's empowerment and child anthropometric failures across 28 sub-Saharan African countries: A cross-level interaction by Gender Inequality Index.

Background: Child undernutrition remains a major global health issue, particularly in sub-Saharan Africa (SSA). Given the important role mothers play in early childhood health and development, we examined how individual-level women's empowerment and country-level Gender Inequality Index (GII) are jointly related with child undernutrition in SSA. Methods: We pooled recent Demographic and Health Surveys from 28 SSA countries. For 137,699 children <5 years old, undernutrition was defined using anthropometric failures (stunting, underweight, wasting). Women's empowerment was assessed using three domains of Survey-based Women's EmPowERment (SWPER) index: attitude to violence, social independence, and decision-making; and country-level gender inequality was measured using GII from United Nations Development Programme. Three-level logistic regression was conducted to examine the joint associations of SWPER and GII as well as their interactions with child anthropometric failures, after adjusting for sociodemographic covariates. Results: Overall, 32.85% of children were stunted, 17.63% were underweight, and 6.68% had wasting. Children of mothers with low-level of empowerment for all domains of SWPER had higher odds of stunting (attitude to violence: OR=1.15; 95% CI, 1.11-1.19; social independence: OR=1.21; 95% CI, 1.17-1.25; decision-making: OR=1.16; 95% CI, 1.12-1.20), and consistent results were found for underweight and wasting. Independent of women's empowerment, country-level GII increased the probability of underweight (ranging ORs=1.46; 95% CI, 1.15-1.85 to 1.50; 95% CI, 1.18-1.90) and wasting (ranging ORs=1.56; 95% CI, 1.24-1.97 to 1.61; 95% CI, 1.27-2.03). Significant interaction was found between women's empowerment and country-level GII for stunting and underweight (p<0.05). Conclusions: In SSA countries with greater gender inequality, improving women's social independence and decision-making power in particular can reduce their children's risk of anthropometric failures. Policies and interventions targeted at strengthening women's empowerment should consider the degree of gender inequality in each country.

Maternal Decision-Making Power and Care-Seeking Behaviors for Acutely Ill Children: A Multilevel Analysis of 33 Sub-Saharan African Countries.

Timely and appropriate healthcare seeking is crucial to reduce child mortality. However, rates of care seeking for acute childhood diseases remain low in sub-Saharan Africa (SSA). This study investigated the association between maternal decision-making power and care-seeking behaviors for children with diarrhea and acute respiratory infection (ARI) in SSA. Demographic and Health Surveys from 33 SSA countries were used in a sample of mother-child pairs (mothers aged 15-49 years; children aged 0-59 months) with a recent child episode of diarrhea (N = 41,729) and ARI (N = 71,966). Maternal decision-making power was defined as making decisions on all four familial topics alone or jointly with the husband/partner. Care-seeking behaviors were measured as seeking care from health providers, other types of providers, and any providers (including both). Multivariable three-level logistic regressions were conducted. Approximately 60% of the sample sought care from any provider (46-48% from health providers versus 13-14% from others). Approximately 28% of mothers had high decision-making power. After adjusting for sociodemographic characteristics, high maternal decision-making power was associated with higher likelihood of seeking care from a health provider for both diarrhea (adjusted odds ratio [aOR] = 1.06, 95% CI = 1.01-1.12) and ARI (aOR = 1.07, 95% CI = 1.03-1.11) and lower likelihood of seeking care from others (aOR = 0.89, 95% CI = 0.82-0.97 for diarrhea; aOR = 0.88, 95% CI = 0.82-0.94 for ARI). Maternal decision-making power was positively associated with their care-seeking behaviors from health providers for acutely ill children in SSA. Women's empowerment interventions that particularly increase women's agency in decision-making may holistically improve health and well-being of the next generation.

The plyometric treatment effects on change of direction speed and reactive agility in young tennis players: a randomized controlled trial.

Aim: The aim of this paper is to determine the effect of 6 weeks of plyometric training on speed, explosive power, pre-planned agility, and reactive agility in young tennis players. Methods: The participants in this study included 35 male tennis players (age 12.14 ± 1.3 years, height 157.35 ± 9.53 cm and body mass 45.84 ± 8.43 kg at the beginning of the experiment). The biological age was calculated and determined for all participants. 18 of the participants were randomly assigned to the control group, and 17 were assigned to the experimental group. Running speed (sprints at 5, 10, and 20 m), change of direction speed (4 × 10, 20 yards, t-test, TENCODS), reactive agility (TENRAG), and explosive power (long jump, single leg triple jump, countermovement jump, squat jump, and single leg countermovement jump) were all tested. The Mixed model (2 × 2) ANOVA was used to determine the interactions and influence of a training program on test results. Furthermore, Bonferroni post hoc test was performed on variables with significant time*group interactions. Results: The results of this research indicate that an experimental training program affected results in a set time period, i.e. 5 out of total 15 variables showed significant improvement after experimental protocol when final testing was conducted. The experimental group showed significantly improved results in the 5 m sprint test in the final testing phase compared to the initial testing phase, this was also the case in comparison to the control group in both measurements. Furthermore, the experimental group showed significant improvement in the single leg countermovement jump in the final test, as well as in comparison to the control group in both measurements. The change of direction speed and reactive agility test also exhibited significant improvement in the final testing phase of the experimental group. Conclusion: The results of this research indicated that a 6-week program dominated by plyometric training can have a significant effect on the improvement of specific motor abilities within younger competitive categories. These results offer valuable insights for coaches in designing diverse tennis-specific scenarios to enhance overall performance, particularly focusing on the neuromuscular fitness of their players.

Comparison of Early and Late Surgeries after Coronary Stent Implantation in Patients with Normal Preoperative Troponin Level: A Retrospective Study.

Current guidelines recommend delaying noncardiac surgery for 6 months after drug eluting stent implantation. However, this recommendation is largely based on limited evidence and various event definitions. Whether early surgery within 6 months of coronary stent implantation increases myocardial injury in patients with normal preoperative high-sensitivity cardiac troponin I (hs-cTnI) has not yet been investigated. This retrospective study assessed patients who received coronary stent implantation and underwent noncardiac surgery (vascular, abdominal, or thoracic) between 2010 and 2017 with normal preoperative hs-cTnI (n = 186). Patients were divided into early (within 6 months of PCI) and late (after 6 months of PCI) groups. The primary endpoint was the incidence of myocardial injury as diagnosed by hs-cTnI within 3 days post-operation. The secondary outcomes were myocardial infarction, stent thrombosis, emergent coronary revascularization, major bleeding (bleeding requiring transfusion or intracranial bleeding), stroke, renal failure, heart failure, or death within 30 days post-operation. Inverse probability treatment weighting (IPTW) was carried out to adjust for the intergroup baseline differences. Myocardial injury occurred in 28.6% (8/28) and 27.8% (44/158) of the early and late groups, respectively, with no difference between groups (odds ratio [OR] 1.067, 95% confidence interval [CI] 0.404, 2.482; p = 0.886). Secondary outcomes did not differ between the groups. IPTW analysis also showed no differences in myocardial injury and secondary outcomes between the groups. In conclusion, early surgery within 6 months after coronary stent implantation did not increase the incidence of myocardial injury in patients with normal preoperative hs-cTnI.

Gender Differences in Iliofemoral Vein Stenting for Chronic Venous Insufficiency.

INTRODUCTION: Little is known about gender's role in chronic venous insufficiency (CVI). The aim of this study was to evaluate the impact of gender on outcomes of iliac vein stenting(IVS) for CVI. METHODS: 866 patients who underwent vein stenting for CVI at one institution from August 2011 to June 2021 were analyzed via retrospective review. Patients were followed up to 5 years after initial stent placement. Presenting symptoms were quantified using Venous Clinical Severity Score(VCSS), Clinical Assessment Score(CAS), and Clinical, Etiology, Anatomy, and Pathophysiology (CEAP) class. Reoperations after initial IVS were recorded. Major reoperations were defined as iliac interventions using venography. Minor reoperations were defined as thermal ablation. Multivariate logistic regression models were used determine odds of any and major reintervention. RESULTS: Compared to females, males pre-operatively presented with a higher mean CEAP class (3.6 vs .3.3; P < .001), VCSS composite (11.3 vs .9.9; P < .001), and smoking history (134 vs .49; P < .001). The 2 groups were similar in age (P = .125), BMI(P = .898), previous DVT (P = .085), diabetes (P = .386), hypertension (P = 1.0), and CAD (P = .499). Multivariate analyses revealed no association between gender and any reintervention (OR, 1.02; 95%CI, .71-1.46; P = .935) or gender and major reintervention (OR, 1.39; 95% CI, .86-2.23 P = .177). There were no differences in number of stents placed (P = .736) or symptomatic improvement at 1 month (P = .951), 3 months (P = .233), 6 months(P = .068), and greater than 1 year (P = .287). At the 1 year follow-up, the male cohort had higher CAS values than females P = .034). Males had larger reduction in composite VCSS than women at 1 year (5.1 vs. 3.8; P = .003) and 3 years (5.3 vs .3.7; P = .031) of follow-up and similar levels of improvement in post-op (4.0 vs .3.5; P = .059), 2 years (4.3 vs .3.8; P = .295), 4-years (5.1 vs .4.6; P = .529), 5 years (5.6 vs .4.2; P = .174), and 6 years (5.93vs.3.3 P = .089). CONCLUSIONS: In a single site study of IVS in patients with CVI, males tended to present worse symptoms than females. After surgery, however, both cohorts showed improvement, and both seemed to improve to the same degree of residual symptoms.

Race differences in iliofemoral vein stenting for chronic venous insufficiency.

INTRODUCTION: Major disparities in outcomes by race are present throughout vascular surgery, yet little has been published on iliac vein stent outcomes by race. This retrospective study assessed iliac vein stent outcomes by patient race. METHODS: Patients who underwent iliac vein stenting at a single institution for chronic venous insufficiency (CVI) from 2011 to 2021 were reviewed. Demographic, preoperative, perioperative, and postoperative data were collected. Self-reported race groups included Asian, Black, Hispanic, and White. Univariate differences were analyzed using χ2 tests for categorical variables and 1-way ANOVA for continuous variables. Outcomes included change in Venous Clinical Severity Score (VCSS) at interval timepoints relative to a preoperative baseline and reinterventions. Logistic regression models were used to determine the unadjusted and adjusted odds ratio (OR) of any minor and major reintervention. Multivariate regression models controlled for demographic and comorbidity characteristics. RESULTS: A total of 827 patients were included. Asian patients were younger and had a greater proportion of male patients, lower Body mass index (BMI), less smoking history, and fewer comorbidities. White patients were more likely to have a history of deep vein thrombosis (DVT). White patients presented with the most severe CVI symptoms as defined by both Clinical-Etiological-Anatomical-Pathophysiological (CEAP) classification and preoperative VCSS composite scores. There were no differences in acute DVT, number of stents deployed, and bilateral versus unilateral stent placement. Black patients had the longest average days of follow-up, followed sequentially by Hispanic, White, and Asian. Black patients had the most reinterventions, while Asian patients had the fewest. Asian patients were less likely to have a major reintervention. No differences in VCSS composite or change in VCSS were observed. CONCLUSIONS: In patients with CVI, Asian patients presented younger and healthier, while White patients presented with the most severe symptoms. No differences were observed in VCSS outcomes, though Black patients had the most reinterventions.

Iliac vein stenting outcomes for patients with superficial venous insufficiency concurrent with deep venous disease.

OBJECTIVE: Many patients will present with chronic proximal venous outflow obstruction (PVOO) and superficial venous insufficiency (SVI) at the time of iliac vein stenting. In the present study, we aimed to determine whether differences in outcomes were present for patients receiving an iliac vein stent according to whether concurrent SVI was present. METHODS: A registry of 553 patients who had undergone iliac vein stent placement for chronic PVOO from 2011 to 2021 was retrospectively analyzed. Two groups of patients were followed for ≤6 years after initial vein stent placement: group 1 (n = 178; 32.2%) had not had SVI before or after stent placement and group 2 (n = 375; 67.8%) had had SVI at initial iliac vein stent procedure. The patients' symptoms were evaluated using the venous clinical severity score (VCSS). Postoperative procedures after initial stent placement were recorded. Postoperative procedures included any operation performed after the index iliac vein stent procedure. Endovenous thermal ablation was classified as a minor postoperative procedure, and any intervention with venography was classified as a major postoperative reintervention. Multivariate regression models were used to determine the odds of a major reintervention or minor procedure postoperatively. RESULTS: Across the two groups, the mean age (group 1, 65.3 years; group 2, 59.9 years; P < .001), body mass index (27.6 vs 26.1 kg/m2; P = .004), diabetes (32.6% vs 17.6%; P < .001), arterial hypertension (68.5% vs 42.1%; P < .001), and coronary artery disease (16.9% vs 9.6%; P = .048) differed significantly. The time to follow-up was similar between the two groups (P = .915). Longitudinally, both groups had had similar improvements in the composite VCSSs. After multivariable adjustment, group 2 was more likely than group 1 (odds ratio, 5.26; 95% confidence interval, 3.33-8.59; P < .001) to have required a postoperative minor procedure, but not a major reintervention. Group 2 had also averaged a shorter interval from the index procedure to a postoperative procedure than group 1 (525.7 days vs 258.1 days; P < .001). CONCLUSIONS: Compared with patients without SVI, those with SVI and chronic PVOO were younger, had had fewer comorbidities, and fared similarly in the change in the composite VCSSs but were more likely to have required a minor procedure and less likely to have required a major reintervention after the index iliac vein stent procedure.

Patients with active venous leg ulcers at the time of iliac vein stenting require more reoperations.

OBJECTIVE: An active venous leg ulcer (VLU) caused by lower extremity venous insufficiency is challenging to treat and will often recur after initially healing. In the present study, we compared the symptomatic outcomes and need for reoperation after iliac vein stenting (IVS) in patients with an active VLU (VLU+) and those without an active VLU (VLU-). METHODS: A single-institution database of patients with chronic venous outflow obstruction who underwent IVS from August 2011 to June 2021 was analyzed. Symptoms were quantified using the venous clinical severity score. The patients were divided into two cohorts: those with (VLU+) and without (VLU-) VLUs. RESULTS: A total of 872 patients (71 VLU+ and 801 VLU-) were identified. Many of the demographics and comorbidities differed between the two cohorts, and these variables were included in the multivariable analysis. On univariate analysis, the VLU+ cohort was more likely to need a major reoperation (odds ratio, 1.94; 95% confidence interval, 1.01-3.52; P = .036). However, on multivariable analysis, the difference was not statistically significant (odds ratio, 1.17; 95% confidence interval, 0.55-2.40; P = .667). Additionally, the VLU+ cohort required a significantly greater mean total of reoperations (1.4 vs 1.0; P = .006) than the VLU- cohort. Comparatively, for patients who underwent at least one reoperation, the difference in the mean total number of reoperations was even greater for the VLU+ cohort (2.6 vs 1.8; P = .001). The results from the Kaplan-Meier log-rank test revealed no differences in the reintervention-free survival time (P = .980). Both cohorts experienced a durable mean reduction in the venous clinical severity score. The ulcer healing rates for the VLU+ cohort at 6, 12, 24, and 36 months were 38%, 47%, 52%, and 59%, respectively. The ulcer recurrence rates for the VLU+ cohort were 4%, 10%, 19%, and 30% at 6, 12, 24, and 36 months, respectively, with a median time to recurrence of 1.2 years. CONCLUSIONS: Patients with active VLUs who underwent a first reintervention after initial IVS, on average, required an additional reintervention.

Symptom Relief and Reintervention after Iliac Vein Stenting Stratified by CEAP Clinical Classification.

BACKGROUND: This study sought to evaluate long-term symptom relief and reintervention rates after iliac vein stenting (IVS) in patients with chronic venous outflow obstruction. METHODS: A single-institution database of patients undergoing IVS from August 2011 to June 2021 was analyzed. Patients were stratified into three cohorts based on the clinical component of the clinical, etiology, anatomical, and pathophysiology (CEAP) classification: C3, C4, and C5/6. Symptoms were quantified using the venous clinical severity score (VCSS). Reintervention was defined as any procedure using venography. Edema, pigmentation, and ulceration progression-free survival as well as reintervention-free survival were assessed with Kaplan Meier analysis. RESULTS: Among 737 total patients, there were 435 C3, 206 C4, and 96 C5/6 patients. The C5/6 cohort had the highest percentage of patients undergo reoperation (36.4%). C5/6 patients yielded the poorest ulceration progression-free survival (P < 0.001) while C3 patients had the poorest skin pigmentation progression-free survival (P = 0.009). On adjusted analysis there was no significant difference in odds of reintervention between study cohorts. Mean composite VCSS scores were significantly different at each yearly post-operative follow-up visit up to 6 years. CONCLUSIONS: The present study is one of the largest investigations of long-term outcomes in IVS patients. Most patients with long-term follow-up experienced an improvement in their composite VCSS. CEAP clinical classification at the time of IVS had a significant influence on the likelihood and quantity of reintervention.

Compression Stocking Compliance Does Not Impact Reintervention or Symptom Change after Iliac Vein Stenting in Patients with Moderate to Severe Lower Extremity Edema.

BACKGROUND: Medical compression stocking (MCS) therapy remains a core treatment for chronic venous disease, particularly in patients with lower extremity edema. This study investigated the impact of postoperative MCS adherence on patients with moderate to severe edema who underwent iliac vein stenting (IVS). METHODS: Patients at a large tertiary care center who underwent IVS from August 2011 to June 2021 were analyzed. Symptoms were quantified using the venous clinical severity score (VCSS) and clinical assessment score (CAS). The criterion for inclusion was moderate or severe lower extremity edema at the time of IVS. Patients were stratified into two cohorts: complete postoperative compression therapy compliance (MCS+) and no postoperative compression therapy use (MCS-). RESULTS: Among 376 patients fitting our study criteria, we identified 168 MCS+ and 208 MCS- patients. The VCSS edema score did not significantly differ between groups (P = 0.179). Postoperatively, the mean changes in VCSS edema at the first postoperative visit, the one-year follow-up, and the two-year follow-up were not significantly different between the MCS+ and MCS- cohorts (P = 0.123, 0.296, and 0.534, respectively). An analysis of CAS for edema revealed that the MCS+ cohort had a modestly better improvement in edema at the 90-day follow-up visit versus the MCS- cohort (P = 0.018), but this difference was not observed in the 30-day (P = 0.834) or six-month follow-up visit (P = 0.755). A multivariate analysis revealed no difference in the need for major intervention (OR 0.93, 95% CI 0.44 to 1.50, P = 0.504). A Kaplan-Meier analysis via log-rank test revealed no difference in reintervention-free survival between groups (P = 0.77). CONCLUSIONS: Many patients with moderate to severe lower extremity edema experience a reduction in their edema after IVS. In our study, compression stocking compliance after surgery had a little impact on edema relief in this population.

Creation of a Short-Range Ordered Two-Dimensional Electron Gas Channel in Al2O3/In2O3 Interfaces.

The tuning of electrical properties in oxides via surface and interfacial two-dimensional electron gas (2DEG) channels is of great interest, as they reveal the extraordinary transition from insulating or semiconducting characteristics to metallic conduction or superconductivity enabled by the ballistic transport of spatially confined electrons. However, realizing the practical aspects of this exotic phenomenon toward short-range ordered and air-stable 2DEG channels remains a great challenge. At the heterointerface formed after deposition of an Al2O3 layer on a nanocrystalline In2O3 layer, a dramatic improvement in carrier conduction equivalent to metallic conduction is obtained. A conductivity increase by a factor of 1013 times that in raw In2O3, a sheet resistance of 850 Ω/cm2, and a room temperature Hall mobility of 20.5 cm2 V-1 s-1 are obtained, which are impossible to achieve by tuning each layer individually. The physicochemical origin of metallic conduction is mainly ascribed to the 2D interfacially confined O-vacancies and semimetallic nanocrystalline InOx (x < 2) phases by the clustered self-doping effect caused by O-extraction from In2O3 to the Al2O3 phase during ALD. Unlike other submetallic oxides, this 2D channel is air-stable by complete Al2O3 passivation and thereby promises applicability for implementation in devices.

Photochemical Hydrogen Doping Induced Embedded Two-Dimensional Metallic Channel Formation in InGaZnO at Room Temperature.

The photochemical tunability of the charge-transport mechanism in metal-oxide semiconductors is of great interest since it may offer a facile but effective semiconductor-to-metal transition, which results from photochemically modified electronic structures for various oxide-based device applications. This might provide a feasible hydrogen (H)-radical doping to realize the effectively H-doped metal oxides, which has not been achieved by thermal and ion-implantation technique in a reliable and controllable way. In this study, we report a photochemical conversion of InGaZnO (IGZO) semiconductor to a transparent conductor via hydrogen doping to the local nanocrystallites formed at the IGZO/glass interface at room temperature. In contrast to thermal or ionic hydrogen doping, ultraviolet exposure of the IGZO surface promotes a photochemical reaction with H radical incorporation to surface metal-OH layer formation and bulk H-doping which acts as a tunable and stable highly doped n-type doping channel and turns IGZO to a transparent conductor. This results in the total conversion of carrier conduction property to the level of metallic conduction with sheet resistance of ∼16 Ω/□, room temperature Hall mobility of 11.8 cm(2) V(-1) sec(-1), the carrier concentration at ∼10(20) cm(-3) without any loss of optical transparency. We demonstrated successful applications of photochemically highly n-doped metal oxide via optical dose control to transparent conductor with excellent chemical and optical doping stability.

Multi-resistive reduced graphene oxide diode with reversible surface electrochemical reaction induced carrier control.

The extended application of graphene-based electronic devices requires a bandgap opening in order to realize the targeted device functionality. Since the bandgap tuning of pristine graphene is limited to 360 meV, the chemical modification of graphene is considered essential to achieve a large bandgap opening at the expense of electrical properties degradation. Reduced graphene oxide (RGO) has attracted significant interest for fabricating graphene-based semiconductors since it has several advantages over other forms of chemically modified graphene; such as tunable bandgap opening, decent electrical properties, and easy synthesis. Because of the reduced bonding nature of RGO, the role of metastable oxygen in the RGO matrix is recently highlighted and it may offer emerging ionic devices. In this study, we show that multi-resistivity RGO/n-Si diodes can be obtained by controlling the RGO thickness at a nanometer scale. This is made possible by (1) a metastable lattice-oxygen drift within bulk RGO and (2) electrochemical ambient hydroxyl (OH) formation at the RGO surface. The effect demonstrated in a p-RGO/n-Si heterojunction diode is equivalent to electrochemically driven reversible electronic manipulation and therefore provides an important basis for the application of O bistability in RGO for chemical sensors and electrocatalysis.

Tuning the electronic structure of tin sulfides grown by atomic layer deposition.

In this study, tin sulfide thin films were obtained by atomic layer deposition (ALD) using Tetrakis(dimethylamino)tin (TDMASn, [(CH3)2N]4Sn) and hydrogen sulfide (H2S). The growth rate of the tin sulfides (SnSx) was shown to be highly dependent on the deposition temperature, and reaction times of 1 second for the TDMASn and H2S were required to reach the saturation regime. Surface morphologies were smooth or rectangular with rounded corners as observed by a field emission scanning electron microscope (FE-SEM) and were dependent on temperature. X-ray diffraction results confirmed that the crystal structure of SnSx can be tuned by changing the ALD temperature. Below 120 °C, SnSx films appeared to be amorphous. In addition, SnSx films were SnS2 hexagonal at 140 and 150 °C and SnS orthorhombic above 160 °C. Similarly, the values of the optical band gap and binding energy showed significant differences between 150 and 160 °C. The electronic structures of SnSx were extracted by UPS and absorption spectroscopy, and the unsaturated Sn 3d molecular orbital (MO) states in the band edge were found to be responsible for the great improvement in electrical conductivity. This study shows that TDMASn-H2S ALD is an effective deposition method for SnSx films, offering a simple approach to tune the physical properties.

The causes of difficult tracheal intubation and preoperative assessments in different age groups.

BACKGROUND: We studied the differences in airway assessment factors among old, middle, and young age groups, and evaluated the frequency and causes of difficult intubation among these groups. METHODS: Patients were divided into young (< 40 yr, n = 75 ), middle (40-59 yr, n = 83), and old (≥ 60 yr, n = 89) group. Airway assessment factors such as head and neck movement, thyromental distance, interincisor gap, dentition, Mallampati score, and Arné score were assessed. After muscle relaxation, cervical joint rigidity and Cormack-Lehane (C-L) grade were assessed. The differences in airway assessment factors between difficult (C-L grade 3, 4) and easy (C-L grade 1, 2) intubation were then examined. Logistic regression analysis was also carried out to identify the extent to which airway assessment factors reflected difficult intubation. RESULTS: As aging, head and neck movement, thyromental distance, and interincisor gap decreased, the grade of dentition, Mallampati score, cervical joint rigidity and the ratio of Arné score > 11 increased. In the old and middle group, the incidence of difficult intubation was increased compared with the young group. Dentition in the young group, Mallampati score and interinsisor gap in the middle group and Mallampati score, cervical joint rigidity in the old group respectively predicted difficult intubation. CONCLUSIONS: Compared to young individuals, middle-aged or elderly adults are likely to experience more difficulty in endotracheal intubation and its predictive factors could vary by age group.

Linear programming method for computing the gamut of object color solid.

Recently there has been great interest in establishing the color gamut of solid colors or the optimum colors. The optimum colors are widely used for quantifying the quality of light sources and evaluating reproduction devices. An enumeration method was developed by Martinez-Verdu et al. [J. Opt. Soc. Am. A 24, 1501 (2007)] for finding optimum colors. However, it was found that the method is too time-costly. In this paper, a linear programming approach is proposed. The proposed method is simple and faster and has the advantage of keeping the characteristics of the true boundary. Comparison of the present method with the method of Martinez-Verdu et al. is also given.