A Label-Free and Ultrasensitive Immunosensor for Detection of Human Chorionic Gonadotrophin Based on Graphene FETs.

We report on a label-free immunosensor based on graphene field effect transistors (G-FETs) for the ultrasensitive detection of Human Chorionic Gonadotrophin (hCG), as an indicator of pregnancy and related disorders, such as actopic pregnancy, choriocarcinoma and orchic teratoma. Pyrene based bioactive ester was non-covalently anchored onto the graphene channel in order to retain the sp² lattice. The G-FET transfer characteristics showed repeatable and reliable responses in all surface modifying steps using a direct current (DC) readout system. The hCG concentration gradient showed a detection limit of ~1 pg·mL-1. The proposed method facilitates the cost-effective and viable production of graphene point-of-care devices for clinical diagnosis

Improved efficiency of graphene/Si Schottky junction solar cell based on back contact structure and DUV treatment

© 2017 Elsevier Ltd A graphene/Si Schottky junction solar cell is commonly fabricated by using the top-window structure. However, reported devices have many drawbacks such as a small active area of 0.11 cm 2 , s-shape in the J-V curves, recombination process of charge carriers at the graphene/textured Si interface, high cost and a complex fabrication process. Here, we report a novel graphene/Si Schottky junction solar cell with a back contact-structure, which has benefits of a simpler fabrication process, lower fabrication cost, and larger active area in comparison with a device fabricated with the previous structure. Additionally, we found that the PMMA residue left on graphene surfaces is the key to eliminate the s-shape in the J-V curves. Thus, the deep UV treatment of the CVD graphene is applied within the wet transfer process to effectively remove the PMMA residue, suppress the behavior of s-shaped kink in J-V curves and enhance the solar cell efficiency. As a result, the recorded power conversion efficiency of 10% is achieved for graphene/textured Si devices without chemical doping and anti-reflection coating, and this value is improved to 14.1% after applying chemical doping. Doped devices also show great stability and retain 84% of the efficiency after 9 days storage in air

Entanglement conditions for two-mode states: Applications

We examine the implications of several recently derived conditions [Hillery and Zubairy, Phys. Rev. Lett. 96, 050503 (2006)] for determining when a two-mode state is entangled. We first find examples of non-Gaussian states that satisfy these conditions. We then apply the entanglement conditions to the study of several linear devices, the beam splitter, the parametric amplifier, and the linear phase-insensitive amplifier. For the first two, we find conditions on the input states that guarantee that the output states are entangled. For the linear amplifier, we determine in the limit of high and no gain, when an entangled input leads to an entangled output. Finally, we show how application of two two-mode entanglement conditions to a three-mode state can serve as a test of genuine three-mode entanglement.Comment: 7 pages, no figures, replaced with published versio

Evaluation of common risk factors of acne in teenagers in Batticaloa district

Acne, or acne vulgaris, is a common skin problem that starts when oil and dead skin cells obstruct the pores. It is leads to psychological dissatisfaction of personality specially among teenagers and adolescents all over the world, including Sri Lanka. In the recent years concern raised regarding acne without gender difference, because people like to be pretty and attractive in the society. Furthermore, majority of the school students are worried about the impact of acne as they are prone to suffer by acne and they naturally feel to be pretty because of their young stage and psycho social believes and thoughts. Therefore, this study was intended to recognize and evaluate the risk factors of acne among school teenagers of Batticaloa district. Respondents of the study included the students from four leading schools in the Batticaloa during the study period. Data collected by interviewer administered questionnaire with the permission of relevant principals of the school. Analysis of data performed by statistical software (SPSS 16.0) and p value <0.05 was considered as significant for all analysis. Majority of participant were Tamil (141=73.44%) ethnic group and most of them resided at urban 136 (70.83%) local authority. The skin type of more than half of the respondents was oily. Onset age of acne lesions for many respondents (39=20.31%) was 16 years. Almost most of them (187=97.40%) had the acne lesion on the face. Acne marks significantly (X2=38.342, p=0.000) leads to major psychological worries on males compared to female students. Food habit with oily meals had significant association to the development of acne, (X2=58.521, p=0.000). Food habit, Body weight, types of skin were identified as the most significant risk factors. Marks of acne is the very serious end results and which has the significant impact on formation of psychological problems among the students specifically in males

Effective chemical treatment for high efficiency graphene/Si Schottky junction solar cells with a graphene back-contact structure

We demonstrate a high-efficiency graphene/Si Schottky junction solar cell with an easy to fabricate graphene back-contact structure and effective chemical treatments. This device effectively overcame the current challenges associated with reported graphene/Si Schottky solar cell structures. The short-circuit current density for such a device is increased by around 20% due to the increase of the active area of this device, compared to previous graphene/Si Schottky junction solar cell devices. The undesirable s-shaped kink in J-V curves, as found in previous works, have been eliminated by using Formamide treatment for 30 min prior to an annealing process in the forming gas. The fill factor of this device is improved by 40% after this treatment, due to the effective removal of the unwanted PMMA residue. Moreover, volatile oxidant vapour and anti-reflection coating are applied within the fabrication process for this device to further improve solar cell performance. An efficiency of 9.5% has successfully been achieved for the fabricated device using the fabrication techniques developed in this work. Our device presents a viable and achievable approach to preparing low-cost and high-performance graphene/Si Schottky junction solar cells

Preparation and Characterization of Poly(1-vinylpyrroli done-co-vinyl acetate)/Poly(methyl methacrylate) Polymer Electrolyte based on TPAI and KI

Polymer electrolytes are promising materials for electrochemical device applications, such as , high energy density rechargeable batteries, supercapacitors, fuel cells, electrochromic displays, etc. Polymer blend electrolytes based on (PVP-co-VAc) and ( PMMA) with different weight ratio of Tetra propyl ammonium iodide (TPAI) and Potassium iodide (KI),  salts using DMSO as solvent. The gel electrolytes were  prepared by solution cast technique. More details can be found in the full paper. Keywords: Gel electrolyte ,Electrochemical Impedance Spectroscopy , Poly(1-vinylpyrrolidone-co- vinyl acetate), poly(methyl meth acryl ate), FTIR

Efficiency enhancement of photovoltaic performance of quasi-solid state dye sensitized solar cell with TPAI and KI binary iodide salt mixture

Quasi-solid-state dye-sensitized solar cells have drawn the attention of scientists and technologists as a potential candidate to supplement future energy needs. The conduction of iodide ions in quasi-solid-state polymer electrolytes and the performance of dye sensitized solar cells (DSSCs) containing such electrolytes can be enhanced by incorporating iodides having appropriate cations. Gel-type electrolytes, were prepared by solution cast technique, based on PVP-co-VAc + PMMA host polymers and mixture of salts Potassium iodide (KI) and tetrapropyl ammonium iodide (TPAI) salts have been used to provide the conducting ions. The salt composition in the binary mixture was varied in order to optimize the performance of solar cells. The electrochemical impedance spectroscopy (EIS) measurements showed that the electrolyte (C6) which contain (KI%25: 5%TPAI) have highest conductivity S/cm at 298 K. The DSSCs with TPAI or KI as the only iodide salt showed the efficiencies 4.136%and 2.532 %, respectively, under AM 1.5(1000 Wm-2) illumination  while the DSSC with mixed cations with (TPAI25%:KI5%) molar ratio shows the  efficiency of 3.179%. Keywords: Binary Iodide, Gel Polymer Electrolyte, Dye-Sensitized Solar Cells, Electrochemical Impedance Spectroscopy

Case of left hip acute pediatric septic arthritis - polymicrobial etiology

Septic arthritis is a true orthopedic emergency, involving a severe bacterial, viral, or fungal joint infection that triggers inflammation and the degeneration of joint tissues. It typically affects joints such as the knee, hip, shoulder, or wrist. Early diagnosis and treatment are crucial to avoid long-term complications. Herein, we describe the case of an 8-year-old male patient who presented with complaints of spontaneous onset of hip pain and an abnormal gait. The patient was diagnosed with left hip septic arthritis and underwent a left hip arthrotomy under general anesthesia (GA). The patient was administered intravenous antibiotics for 21 days while being kept on non-weight-bearing mobilization. After 3 weeks, the patient's intravenous antibiotics were switched to oral antibiotics for the next 3 weeks. On the second follow-up visit, the patient showed significant improvement, with laboratory findings within normal limits

Severe androgenetic alopecia as a maker of metabolic syndrome in male patients of androgenetic alopecia: a hospital based case control study

Background: Several previous studies have investigated the association between androgenetic alopecia (AGA) and metabolic syndrome (MS), with inconsistent results. Objectives of the study were to study the prevalence of metabolic syndrome in male patients of androgenetic alopecia and compare with control population and study the relationship of metabolic syndrome with different grades of AGA.Methods: This prospective hospital based case control study included 100 new clinically diagnosed males of androgenetic alopecia, and age and sex matched control group. Assessment for presence of various components of metabolic syndrome was done following a uniform protocol in cases and controls. AGA was classified as per Hamilton –Narwood classification, grade I to III was classified as mild –moderate and grade IV and higher as severe AGA.Results: Of the 100 male AGA patients (age range 21-50, mean 34.49), 36 had grade II AGA, 24 had grade III AGA, 20 had grade IV AGA, 15 had grade V AGA and 5 had grade VI AGA. Among AGA patients, 60 of patients had mild-moderate AGA and 40 patients had severe AGA. Metabolic syndrome was statistically significantly more common in patients with AGA compared to controls. Among patients of AGA, metabolic syndrome was statistically significantly present in severe AGA compared to mild-moderate AGA. Among the evaluated parameters, like blood pressure, fasting blood sugar, dyslipedemia, abdominal obesity, all were significantly more common in AGA patients compared to controls except abdominal obesity.Conclusions: In the present study, metabolic syndrome was found to be 4.6 times more common in patients of androgenetic alopecia as compared to controls, being statistically significant, and more common in those with severe grades. This suggests that androgenetic alopecia patients especially with severe grades are at risk of metabolic syndrome and other cardiovascular diseases