Preventing cervical cancer: primary and secondary measures

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Antibiotic prescription patterns for acute diarrhea in a hospital in Shanghai in 2016: a cross-sectional study

Background: Unnecessary antibiotic use increases the risk for antibiotic resistance. The rates of antibiotic use for upper respiratory infections are high in hospitals in China. Although most guidelines advise against the use of antibiotics for acute diarrhea, little is known about antibiotic use practices for acute diarrhea in China. Methods: A retrospective prescription review from a Shanghai hospital outpatient electronic health records system was conducted from 1 January 2016 to 30 December 2016. Records were included for adult patients. The microbial resistance seasonal data in 2016 were extracted. Chi-squared and multivariable logistic regression and adjusted odd ratio (aOR) were used to assess the relationships between demographic characteristics and antibiotic prescribing. Results: In total, there were 16,565 prescriptions, 16,060 prescriptions were included in the final analysis after excluding the follow up visits. There were 12,131 (76%) prescriptions with antibiotics prescribed. 5505 (45%) of the antibiotics prescribed were injectable. Of the antibiotics prescribed, levofloxacin was the most frequent (85%), followed by various cephalosporins (14%). Of the cephalosporin prescriptions, 3rd generation products were the most common (97%). Treatment with oral rehydration salts (ORS) was prescribed 34 (0.2%) times, probiotics were prescribed 3414 (21%) times and smectite was prescribed 2209 (14%) times. Multivariable regression analysis showed that those more likely to receive antibiotics were age 31-50 aOR 1.3 (1.1-1.4), p<0.001, evaluated in the late evening (11pm to 7am) aOR 2.6 (2.2-2.9) p<0.001, in the early evening (6pm-11pm) aOR 2.0 (1.8-2.2) p<0.001, in the summer (June-August) aOR 1.7 (1.5-1.9) p<0.001. At the same time, the Gram positive and Gram negative resistance rates to levofloxacin exceeded 40%, including 50% of E. coliisolates. Conclusion: High rates of antibiotic use were observed for acute diarrhea in this hospital. Given the inappropriateness of antibiotics for acute diarrhea and the nonsensical high rates of of intravenous levofloxacin use and the concurrent high rates of the levofloxacin resistance, a more effective antibiotic stewardship program is needed to improve patient outcomes, reduce costs, reinforce policy and address the underlying causes of antibiotic abuse.published_or_final_versio

Antibiotic use among future health professionals: A multicentre cross sectional study of Chinese medical student

Background: Antibiotic use leads to antibiotic resistance and antibiotic misuse is high in China and other developing countries. This may arise from beliefs and behaviours of doctors and the pressure they receive from patients. This study aims to understand antibiotic use behaviour for self-limited illness among medical students - the future healthcare professionals. Methods: This is part of a large cross-sectional study of Chinese university students of science, social science and humanities, and medicine. An electronic survey health belief model (HBM) questionnaire was distributed at six universities in China from September to November 2015. The score assessment was based on the constructs of HBM theory. Chi-squared and multivariable logistic regression and adjusted odd ratios (aOR) were used to assess the relationship between demographic characteristics, antibiotic use knowledge and behaviour. Results: In total, 11455 students were asked to participate and 11192 (97.5%) completed the questionnaires. 1819 medical students completed the survey. In the past month 529 (29%) medical students reported at least one self-limited illness. Of those, 285 (54%) self-medicated and 77 (27%) of them used antibiotics. 111 (21%) saw a doctor among whom 64 (58%) received antibiotics. 133 (25%) did nothing. In the past year, 279 (15%) of students used antibiotics for prophylaxis, 273 (15%) ever demanded an antibiotic from a doctor, 1166 (64%) kept a personal stock of antibiotics, 1034 (57%) bought antibiotics at a pharmacy, 97% of these without a prescription. Students with high HBM scores about antibiotics were significantly less likely to self-medicate with antibiotics (aOR 0.37, 95% CI 0.15-0.91, p=0.031), to use antibiotics for prophylaxis (aOR 0.35, 95% CI 0.21-0.60, p<0.0001) or demand an antibiotic (aOR 0.46, 95% CI 0.26-0.81, p=0.007). Students whose father has a higher education level, whose mother is a doctor or who are from urban areas were more likely to stock antibiotics and self-medicate. Conclusion: High rates of antibiotic self-medication (54%) and stocking (64%) were found among medical students. Along with the high rates of unnecessarily prescribed antibiotics by doctors (58%), there is clearly a need for effective antibiotic stewardship and training programs in Chinese healthcare institutions and medical schools.published_or_final_versio

CuInS2/ZnS nanocrystals as sensitisers for NiO photocathodes

Nickel oxide (NiO) is the most universally studied photocathode to date, however, its poor fill factor (FF) makes its efficiency much lower than its counterpart, n-type photoanodes. Its significance in photovoltaics is based on the potential to fabricate tandem photoelectrodes in order to enhance the overall efficiency of the existing devices. Furthermore, limited work on the sensitisation of NiO with semiconducting nanocrystals (NCs) exists. For the first time, we have fabricated NiO photocathodes sensitised with aqueous CuInS2/ZnS NCs. The NCs were chemically bound to the NiO films with the aid of carboxyl and thiol groups. This was achieved without modifying the bulk surface properties of NiO. Binding of the NCs was investigated using TEM, SEM, XPS, XANES, EXAFS modelling and ToF-SIMS. NiO films were assembled into CuInS2/ZnS NC sensitised photocathodes and their photovoltaic properties were compared to those of unsensitised and dye-sensitised NiO solar cells. We demonstrate that nontoxic NCs can be used to sensitise NiO photocathodes to achieve an (almost) all-inorganic system

Patterned growth of InGaN/GaN quantum wells on freestanding GaN grating by molecular beam epitaxy

We report here the epitaxial growth of InGaN/GaN quantum wells on freestanding GaN gratings by molecular beam epitaxy (MBE). Various GaN gratings are defined by electron beam lithography and realized on GaN-on-silicon substrate by fast atom beam etching. Silicon substrate beneath GaN grating region is removed from the backside to form freestanding GaN gratings, and the patterned growth is subsequently performed on the prepared GaN template by MBE. The selective growth takes place with the assistance of nanoscale GaN gratings and depends on the grating period P and the grating width W. Importantly, coalescences between two side facets are realized to generate epitaxial gratings with triangular section. Thin epitaxial gratings produce the promising photoluminescence performance. This work provides a feasible way for further GaN-based integrated optics devices by a combination of GaN micromachining and epitaxial growth on a GaN-on-silicon substrate

Quantum fluctuations in high field magnetization of 2D square lattice J1-J2 antiferromagnets

The J1-J2 square lattice Heisenberg model with spin S=1/2 has three phases with long-range magnetic order and two unconventionally ordered phases depending on the ratio of exchange constants. It describes a number of recently found layered vanadium oxide compounds. A simple means of investigating the ground state is the study of the magnetization curve and high-field susceptibility. We discuss these quantities by using the spin-wave theory and the exact diagonalization in the whole J1-J2 plane. We compare both results and find good overall agreement in the sectors of the phase diagram with magnetic order. Close to the disordered regions the magnetization curve shows strong deviations from the classical linear behaviour caused by large quantum fluctuations and spin-wave approximation breaks down. On the FM side (J1<0) where one approaches the quantum gapless spin nematic ground state this region is surprisingly large. We find that inclusion of second order spin-wave corrections does not lead to fundamental improvement. Quantum corrections to the tilting angle of the ordered moments are also calculated. They may have both signs, contrary to the always negative first order quantum corrections to the magnetization. Finally we investigate the effect of the interlayer coupling and find that the quasi-2D picture remains valid up to |J_\perp/J1| ~ 0.3.Comment: 13 pages, 6figure

Wideband THz time domain spectroscopy based on optical rectification and electro-optic sampling

We present an analytical model describing the full electromagnetic propagation in a THz time-domain spectroscopy (THz-TDS) system, from the THz pulses via Optical Rectification to the detection via Electro Optic-Sampling. While several investigations deal singularly with the many elements that constitute a THz-TDS, in our work we pay particular attention to the modelling of the time-frequency behaviour of all the stages which compose the experimental set-up. Therefore, our model considers the following main aspects: (i) pump beam focusing into the generation crystal; (ii) phase-matching inside both the generation and detection crystals; (iii) chromatic dispersion and absorption inside the crystals; (iv) Fabry-Perot effect; (v) diffraction outside, i.e. along the propagation, (vi) focalization and overlapping between THz and probe beams, (vii) electro-optic sampling. In order to validate our model, we report on the comparison between the simulations and the experimental data obtained from the same set-up, showing their good agreement

p38 Mapk signal pathway involved in anti-inflammatory effect of chaihu-shugan-san and shen-ling-bai-zhu-san on hepatocyte in non-alcoholic steatohepatitis rats

Background: Traditional Chinese Medicine (TCM), has over thousands-of-years history of use. Chaihu-Shugan-San (CSS), and Shen-ling-bai-zhu-San (SLBZS), are famous traditional Chinese herbal medicine formulas, which have been used in China, for the treatment of many chronic diseases.Materials and Methods:This study investigated the anti-inflammatory effects of CSS and SLBZS on signaling molecules involved in p38 mitogen-activated protein kinase (p38 MAPK), pathway on hepatocytes of non-alcoholic steatohepatitis (NASH), rats induced by high fat diet. SD male rats were randomly divided into 8 groups: negative control group, model control group, high (9.6g/kg/day)/low (3.2g/kg/day)-dose CSS group, high (30g/kg/day)/low (10g/kg/day)-dose SLBZS group, high (39.6g/kg/day)/low (13.2g/kg/day)-dose integrated group. The rats of NASH model were induced by feeding a high-fat diet. After 16, wks, Hepatocytes were isolated from 6, rats in each group by collagenase perfusion. The liver histopathological changes and serum inflammatory cytokines TNF-α, IL-6 were determined. The proteins of TLR4,  phosphor-p38 MAPK and p38 MAPK involved in p38 MAPK signal pathway were assayed.Results: The statistical data indicated the NASH model rats reproduced typical histopathological features of NASH in human. CSS and SLBZS ameliorated lipid metabolic disturbance, attenuated NASH progression, decreased the levels of TNF-α and IL-6 in serum, as well as inhibited TLR4 protein expression, p38 MAPK phosphorylation, and activation of p38 MAPK. In conclusion, CSS and SLBZS might work as a significant anti-inflammatory effect on hepatocyte of NASH by inhibiting the activation of TLR4, p-p38 MAPK and p38 MAPK involved in p38 MAPK signal pathway.Conclusion: To some extent, CSS and SLBZS may be a potential alternative and complementary medicine to protect against liver injury, alleviate the inflammation reaction, moderate NASH progression.Key words: p38 mitogen-activated protein kinase; Toll like receptor 4; Hepatocytes; Non-alcoholic Steatohepatitis; Traditional Chinese medicine

In silico Assessment of Drug-like Properties of Alkaloids from Areca catechu L Nut

Purpose: To investigate in silico the drug-like properties of alkaloids (arecoline, arecaidine, guvacine, guvacoline, isoguvacine, arecolidine and homoarecoline) obtained from the fruits of Areca catechu L (areca nut).Methods: All chemical structures were re-drawn using Chemdraw Ultra 11.0. Furthermore, software including Bio-Loom for Windows - version 1.5, Molinspiration Property Calculator and ACD/I-LAB service were used to predict the drug-like properties of the alkaloids, including relative molecular mass (MW), partition coefficient log P (cLog P), number of hydrogen bond donors (HBD), number of hydrogen bond acceptors (HBA), topological polar surface area (TPSA), number of rotatable bonds (NROTB), pKa, and aqueous solubility at a given pH (LogS). In addition, Lipinski’s rule was used to evaluate druglike properties.Results: From our research, MWs of the seven compounds were all &lt; 500. HBD and cLog P values of the seven compounds were all &lt; 5, and HBA values were all &lt; 10. In addition, TPSA value of each compound was &lt; 60 Å2, and NROTB value was &lt; 10. Besides, pKa values of the seven alkaloids were &gt; 7.5; furthermore, they possess good solubility at pH 1.0, 5.0, and 7.0.Conclusion: All the seven alkaloids possess good drug-like properties, and demonstrated good oral absorption and bioavailability. The results also suggest that these compounds can be further developed into new oral drugs for treating certain diseases.Keywords: Areca catechu L, Areca nut, Drug-like properties, Alkaloids, Arecoline, Arecaidine, Guvacine, Guvacoline, Isoguvacine, Arecolidine, Homoarecoline, In silic

Geometric Friction Directs Cell Migration

In the absence of environmental cues, a migrating cell performs an isotropic random motion. Recently, the breaking of this isotropy has been observed when cells move in the presence of asymmetric adhesive patterns. However, up to now the mechanisms at work to direct cell migration in such environments remain unknown. Here, we show that a nonadhesive surface with asymmetric microgeometry consisting of dense arrays of tilted micropillars can direct cell motion. Our analysis reveals that most features of cell trajectories, including the bias, can be reproduced by a simple model of active Brownian particle in a ratchet potential, which we suggest originates from a generic elastic interaction of the cell body with the environment. The observed guiding effect, independent of adhesion, is therefore robust and could be used to direct cell migration both in vitro and in vivo