Clinical features-based machine learning models to separate sexually transmitted infections from other skin diagnoses.

INTRODUCTION: Many sexual health services are overwhelmed and cannot cater for all the individuals who present with sexually transmitted infections (STIs). Digital health software that separates STIs from non-STIs could improve the efficiency of clinical services. We developed and evaluated a machine learning model that predicts whether patients have an STI based on their clinical features. METHODS: We manually extracted 25 demographic features and clinical features from 1315 clinical records in the electronic health record system at Melbourne Sexual Health Center. We examined 16 machine learning models to predict a binary outcome of an STI or a non-STI diagnosis. We evaluated the models' performance with the area under the ROC curve (AUC), accuracy and F1-scores. RESULTS: Our study included 1315 consultations, of which 36.8% (484/1315) were diagnosed with STIs and 63.2% (831/1315) had non-STI conditions. The study population predominantly consisted of heterosexual men (49.5%, 651/1315), followed by gay, bisexual and other men who have sex with men (GBMSM) (25.7%), women (21.6%) and unknown gender (3.2%). The median age was 31 years (intra-quartile range (IQR) 26-39). The top 5 performing models were CatBoost (AUC 0.912), Random Forest (AUC 0.917), LightGBM (AUC 0.907), Gradient Boosting (AUC 0.905) and XGBoost (AUC 0.900). The best model, CatBoost, achieved an accuracy of 0.837, sensitivity of 0.776, specificity of 0.831, precision of 0.782 and F1-score of 0.778. The key important features were lesion duration, type of skin lesions, age, gender, history of skin disorders, number of lesions, dysuria duration, anorectal pain and itchiness. CONCLUSIONS: Our best model demonstrates a reasonable performance in distinguishing STIs from non-STIs. However, to be clinically useful, more detailed information such as clinical images, may be required to reach sufficient accuracy.

Selective Charge Carrier Transport and Bipolar Conduction in an Inorganic/Organic Bulk-Phase Composite: Optimization for Low-Temperature Thermoelectric Performance.

Abundant conducting polymers are promising organic substances for low-temperature thermoelectric applications due to their inherently low thermal conductivities. By introducing a conducting polymer filler (PEDOT:PSS─poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonic acid)) into a representative inorganic thermoelectric matrix (Bi2Te3), a bulk-phase composite (i.e., inorganic matrix/organic filler) for low-temperature thermoelectric applications is proposed. This composite hosts an interfacial energy barrier between the inorganic and organic components, facilitating controlled carrier transport based on its energy level, known as the energy filtering effect, and thus the composite exhibits a highly improved Seebeck coefficient compared to pristine Bi2Te3. The composite also displays a completely different temperature dependence on the Seebeck coefficient from Bi2Te3 due to its distinct bipolar conduction tendency. By regulation of the energy filtering effect and bipolar conduction tendency, the composite undergoes noticeable variations in the Seebeck coefficient, resulting in a significantly enhanced power factor. Furthermore, the composite shows a substantially reduced thermal conductivity compared to Bi2Te3 because it has lower carrier/lattice thermal contributions, possibly attributed to its high carrier/phonon scattering probabilities. Owing to the superior power factor and reduced thermal conductivity, the composite exhibits markedly enhanced thermoelectric performance, achieving a maximum figure of merit of approximately 1.26 at 380 K and an average figure of merit of approximately 1.23 in the temperature range of 323-423 K. The performance of the composite is competitive with previously reported n-type Bi2Te3 binary or ternary analogues. Therefore, the composite is highly expected to be a promising n-type counterpart of p-type Bi2Te3-based alloys for various low-temperature thermoelectric applications.

Determining the screening frequency for sexually transmitted infections for people who use HIV pre-exposure prophylaxis: a systematic review and meta-analysis.

OBJECTIVES: Although the World Health Organization recommends 'frequent' screening of sexually transmitted infections (STI) for people who use pre-exposure prophylaxis for HIV, there is no evidence for optimal frequency. METHODS: We searched five databases and used random-effects meta-analysis to calculate pooled estimates of STI test positivity. We narratively synthesized data on secondary outcomes, including adherence to recommended STI screening frequency and changes in STI epidemiology. RESULTS: Of 7477 studies, we included 38 for the meta-analysis and 11 for secondary outcomes. With 2-3 monthly STI screening, the pooled positivity was 0.20 (95% confidence interval [CI]: 0.15-0.25) for chlamydia, 0.17 (95% CI: 0.12-0.22) for gonorrhea, and 0.07 (95% CI: 0.05-0.08) for syphilis. For chlamydia and gonorrhea, the positivity was approximately 50% and 75% lower, respectively, in studies that screened 4-6 monthly vs 2-3 monthly. There was no significant difference in the positivity for syphilis in studies that screened 4-6 monthly compared to 2-3 monthly. Adherence of clients to recommended screening frequency varied significantly (39-94%) depending on population and country. Modeling studies suggest more frequent STI screening could reduce incidence. CONCLUSION: Although more frequent STI screening could reduce delayed diagnoses and incidence, there remain significant knowledge gaps regarding the optimal STI screening frequency.

Effects of the Interface between Inorganic and Organic Components in a Bi2Te3-Polypyrrole Bulk Composite on Its Thermoelectric Performance.

We provided a method to hybridize Bi2Te3 with polypyrrole, thus forming an inorganic/organic bulk composite (Bi2Te3-polypyrrole), in which the effects of energy band junction and phonon scattering were expected to occur at the interface of the two components. Bi2Te3-polypyrrole exhibited a considerably high Seebeck coefficient compared to pristine Bi2Te3, and thus it recorded a somewhat increased power factor despite the loss in electrical conductivity caused by the organic component, polypyrrole. Bi2Te3-polypyrrole also exhibited much lower thermal conductivity than pristine Bi2Te3 because of the phonon scattering effect at the interface. We successfully brought about the decoupling phenomenon of electrical and thermal properties by devising an inorganic/organic composite and adjusting its fabrication condition, thereby optimizing its thermoelectric performance, which is considered the predominant property for n-type binary Bi2Te3 reported so far.

Crystal alignment of a LiFePO4 cathode material for lithium ion batteries using its magnetic properties.

We suggest a way to control the crystal orientation of LiFePO4 using a magnetic field to obtain an advantageous structure for lithium ion conduction. We examined the magnetic properties of LiFePO4 such as magnetism and magnetic susceptibility, which are closely related to the crystal rotation in an external magnetic field, and considered how to use these properties for desired crystal orientation; thus, we successfully fabricated the crystal-aligned LiFePO4, in which the b-axis was highly aligned perpendicular to the surface of a current collector. Considering the low lithium ion conductivity of LiFePO4 inherently originated from its one-dimensional path for lithium ion diffusion, the crystal-aligned LiFePO4 potentially facilitates favorable transport kinetics for lithium ions during the charge/discharge process in lithium ion batteries. The crystal-aligned LiFePO4 should afford lower electrode polarization than pristine LiFePO4, and thus the former consistently exhibited higher reversible capacity than the latter.

The Association Between Serum Leptin Levels and Post-Stroke Depression: A Retrospective Clinical Study.

OBJECTIVE: To investigate the question of whether serum leptin levels might be associated with post-stroke depression. METHODS: We studied 130 patients who experienced a first episode of stroke of more than three months' duration, without any previous history of depression or speech disorders. Data were collected regarding the patient demographics, depressive mood (Diagnostic and Statistical Manual of Mental Disorders 4th edition [DSM-IV] criteria and Beck Depression Inventory) and serum leptin levels measured by an enzyme-linked immunosorbent assay (ELISA). In addition, the Korean version of Modified Barthel Index (K-MBI) and Korean version of Mini-Mental State Examination (K-MMSE) were used to assess the subjects' independence, in regard to the activities of daily living and cognition. A statistical analysis was performed to determine differences the serum leptin levels between patients with depression and those without depression, and to determine the difference in the MBI and K-MMSE scores between the groups separated according to the serum leptin levels. RESULTS: Higher serum leptin levels were observed in patients with depression, compared with those without depression (38.5 ng/mL [range, 25.1-59.2 ng/mL] vs. 8.2 ng/mL [range, 4.9-17.8 ng/mL]; p<0.01. The serum leptin level showed an association with depression (odds ratio, 1.21; 95% confidence interval, 1.01-1.45; p=0.021). The K-MMSE and K-MBI improvement scores were lower, with statistical significance, in the group with the highest leptin level (>30 mg/dL), compared to the other two groups. CONCLUSION: High serum leptin levels are associated with depression after stroke, and patients with elevated serum leptin levels were disadvantaged in regard to functional and cognitive outcomes.

Investigation of reaction mechanisms of bismuth tellurium selenide nanomaterials for simple reaction manipulation causing effective adjustment of thermoelectric properties.

We synthesized ternary n-type bismuth tellurium selenide nanomaterials for thermoelectric applications via a water-based chemical reaction under an atmospheric environment. In this work, bismuth nitrate was employed as a bismuth precursor and was hydrolyzed to form bismuth hydroxide in an aqueous solution. Ascorbic acid was used to dissolve the bismuth hydroxide and give a reactive bismuth source (Bi(3+) ions) that was able to react with anion sources (Te(2-)/Se(2-) ions). Ascorbic acid played a role in reducing bismuth hydroxide to an unreactive bismuth source (bismuth particles, Bi(0)). We confirmed that ascorbic acid dissolved or reduced bismuth hydroxide depending on the solution pH. Because either Bi(3+) ions or bismuth particles were generated depending on the pH, the nanomaterial stoichiometry was pH dependent. Nanomaterials prepared at various pH levels were individually sintered using a spark plasma sintering process to measure their thermoelectric transport properties (i.e., carrier concentration, electrical resistivity, Seebeck coefficient, and thermal conductivity). We observed how the transport properties were affected through adjustment of the pH of the reaction and found an appropriate pH for optimizing the transport properties, which resulted in enhancement of the thermoelectric performance.

Improved photovoltaic properties of polymer solar cells with a phenyl compound as an additive.

A phenyl compound with electron withdrawing substituents, 3-fluoro-4-cyanophenol (FCP), was used as an additive in polymer solar cells with a P3HT [poly(3-hexyl thiophene)]:PCBM [[6,6]-phenyl-C61-butyric acid methyl ester] blend film. Under simulated solar illumination of AM 1.5 (100 mW/cm2), the devices fabricated using a P3HT:PCBM (1:0.9 w:w) layer blended with 5 wt% of FCP achieved an enhanced power conversion efficiency (PCE) of 4.8% due to the improved short circuit current and fill factor, as compared to reference cells with PCE = 4.1%. UV-visible absorption spectra, X-ray measurements and carrier mobility studies revealed that FCP facilitated the ordering of the P3HT chains, resulting in higher absorbance, larger crystal size, closer packing and enhanced hole mobility.

Inverted polymer solar cells with an ultrathin lithium fluoride buffer layer.

An ultrathin lithium fluoride (LiF) buffer layer was applied to inverted polymer solar cells with P3HT [poly(3-hexylthiophene)]:PCBM [[6,6]-phenyl C61-butyric acid methyl ester] blend films. By inserting the LiF layer between the transparent electrode and the P3HT:PCBM blend film, all parameters, including the short-circuit current, the open-circuit voltage and the fill factor, were enhanced compared to those of a reference cell without the LiF layer. The power conversion efficiency of the device with the LiF layer was thereby improved by more than 300% relative to the reference cell.

Significant enhancement in the thermoelectric performance of a bismuth telluride nanocompound through brief fabrication procedures.

A binary BiTe nanocompound for thermoelectric applications was prepared via a water-based chemical reaction under atmospheric conditions. We attempted to increase the carrier mobility of the nanocompound by adopting a post-thermal treatment consisting of calcination and reduction at different temperatures. We also tried to control the carrier density of the compound by adjusting the stoichiometry of the atomic constituents. We measured other transport properties (i.e., electrical resistivity, Seebeck coefficient, and thermal conductivity) and observed how these properties were affected by both the carrier mobility and the carrier density. We derived the thermoelectric performance, as captured by the figure of merit (ZT), from the transport properties and discussed the effect of such properties on the ZT value. The nanocompound exhibited a very competent ZT value (0.91 at 100 °C), which is one of the best thermoelectric performances of chemically synthesized BiTe materials.

Development of photocatalytic TiO2 nanofibers by electrospinning and its application to degradation of dye pollutants.

We have developed photocatalytic TiO2 nanofibers for the treatment of organic pollutants by using electrospinning method. We found that the optimized electrospinning conditions (electric field and flow rate) were 0.9 kV cm(-1) and 50 microL min(-1). After annealing at 550 degrees C for 30 min, we fabricated TiO2 nanofibers (average 236 nm thick) with anatase crystalline phase. To increase photocatalytic activity and effective surface area, we coated photocatalytic TiO2 particles on the TiO2 nanofibers by using sol-gel method. The degradation rate (k'=85.4x10(-4) min(-1)) of composite TiO2 was significantly higher than that (15.7x10(-4) min(-1)) of TiO2 nanofibers and that (14.3x10(-4) min(-1)) of TiO2 nanoparticles by the sol-gel method. Therefore, we suggested that the composite TiO2 of nanofibers and nanoparticles be suitable for the degradation of organic pollutants.