Third-order nonlinear optical study on sublimated/Langmuir-Blodgett thin films of lanthanide porphyrin phthalocyanine dimer/heterodimer and symmetric trimer systems by time-resolved non-degenerate four-wave mixing

Time-resolved four-wave mixing (TRFWM) studies have been carried out on sublimated films of the neodymium phthalocyanine dimer Pc[superscript 2-Nd[superscript III]Pc[superscript point], the cerium porphyrin phthalocyanine sandwich mixed heterodimer Pc[superscript 2-]Ce[superscript IV]TPP[superscript 2-], the cerium porphyrin phthalocyanine symmetric trimer TPP[superscript 2-]Ce[superscript III]Pc[superscript 2-]Ce[superscript III]TPP[superscript 2-], the neodymium porphyrin phthalocyanine trimer Pc[superscript 2-]Nd[superscript III]TPP[superscript 2-]Nd[superscript III]Pc[2-], and Langmuir-Blodgett films of the cobalt porphyrin phthalocyanine mixed dimer CoPC [subscript 22][superscript 4+] / H[subscript 2]PcTS [subscript 4-]. In this work, we have presented a number of novel results: the first non-degenerate time-resolved four-wave mixing (NDTRFWM) experiment on a sublimated film, the first observation and identification of the diffusion contribution to the degrating process, the first observation and identification of photorefractive effect in an organic multimer thin film, and the first observation and identification of a correlated phonon mode shifting phenomenon. The absolute values of the third-order nonlinear optical susceptibility [chi superscript (3)] of the samples have been determined by comparing the third-order nonlinear optical responses of the samples with those of a slide of reference fused quartz under the same experimental conditions. It is shown that TRFWM is a very useful, very sensitive and very powerful tool to investigate the dynamics of the third-order nonlinear optical processes in a medium, especially those that can not be detected by transient absorption and other means of probing nonlinear optical properties. Through this work, it can be seen that lanthanide porphyrin phthalocyanine dimer/heterodimer trimer/heterotrimer systems could be a new family of organic materials most promising for the investigation and the applications of photorefractive effect. They are very versatile and have a great potential as nonlinear optical materials

The contact mode of a joint interface based on improved deep neural networks and its application in vibration analysis

The precision of the contact model for a joint interface strongly depends on the fractal dimension and fractal roughness coefficient. In this paper, an improved deep neural network method was adopted to predict the surface appearance parameters. In order to meet the high accuracy requirements for the prediction results of the contact model, a novel surface appearance prediction model was established utilizing a regularized deep belief network. The Bayesian regularization strategy was used to reduce the network weights during unsupervised training, which can effectively restrain the contribution of unimportant neurons. This allows to limit the occurrence of overfitting, and the layer-by-layer training was performed for each hidden layer based on a continuous transfer function. Meanwhile, the surface appearance parameters of the joint interface could be obtained by plugging arbitrary machining parameters into the training model. The specific contact model was then established based on fractal theory by applying the above-mentioned prediction results. The parameters of the joint interface were used to simulate the frequencies and vibration modes of frame-shaped structural parts. The contact model was validated by comparing the simulation results with experimental data. The proposed model is expected to provide a theoretical basis for optimizing the structure and improving the accuracy of computerized numerical control machines

Pressured HIV testing "in the name of love": a mixed methods analysis of pressured HIV testing among men who have sex with men in China.

INTRODUCTION: HIV testing has rapidly expanded into diverse, decentralized settings. While increasing accessibility to HIV testing is beneficial, it may lead to unintended consequences such as being pressured to test. We examined the frequency, correlates and contexts of pressured HIV testing among Chinese men who have sex with men (MSM) using mixed methods. METHODS: We conducted an online survey of MSM (N = 1044) in May 2017. Pressured HIV testing was defined as being forced to test for HIV. We conducted logistic regression analysis to determine the associations between pressured HIV testing and socio-demographic and sexual behavioural factors. Follow-up interviews (n = 17) were conducted with men who reported pressured testing and we analysed qualitative data using a thematic analysis approach. RESULTS: Ninety-six men (9.2%) reported experiencing pressure to test for HIV. Regular male sex partners were the most common source of pressure (61%, 59/96), and the most common form of pressure was a threat to end a relationship with the one who was being pressured (39%, 37/96). We found a higher risk of pressured testing in men who had only used HIV self-testing compared to men who had never self-tested (AOR 2.39 (95%CI: 1.38 to 4.14)). However, this relationship was only significant among men with low education (AOR 5.88 (95% CI: 1.92 to 17.99)) and not among men with high education (AOR 1.62 (95% CI: 0.85 to 3.10)). After pressured testing, about half of men subsequently tested for HIV (55%, 53/96) without pressure - none reported being diagnosed with HIV. Consistent with this finding, qualitative data suggest that perceptions of pressure existed on a continuum and depended on the relationship status of the one who pressured them. Although being pressured to test was accompanied by negative feelings, men who were pressured into testing often changed their attitude towards HIV testing, testing behaviours, sexual behaviours and relationship with the one who pressured them to test. CONCLUSION: Pressured HIV testing was reported among Chinese MSM, especially from men with low education levels and men who received HIV self-testing. However, in some circumstances, pressure to test helped MSM in several ways, challenging our understanding of the role of agency in the setting of HIV testing

Missed Opportunities for Human Immunodeficiency Virus and Syphilis Testing Among Men Who Have Sex With Men in China: A Cross-Sectional Study.

BACKGROUND: Men who have sex with men (MSM) are at high risk of human immunodeficiency virus (HIV)/syphilis. To inform strategies for dual testing, we describe patterns of HIV/syphilis testing, and examine factors associated with never testing for HIV/syphilis in China. METHODS: An online survey (2016) was completed by MSM from 8 cities: men born biologically male, 16 years or older, and had sex with another man at least once during their lifetime. Demographic, sexual behavioral, and HIV/syphilis testing data were collected. Multivariable multinomial logistic regression identified characteristics associated with men who never tested for HIV/syphilis compared with men who ever tested for both infections. RESULTS: Overall, 2105 men participated. Among them, 35.1% (738/2105) never tested for HIV/syphilis, and in those ever tested for HIV, only half (54.0%, 709/1312) had tested for syphilis. Relative to men who had ever tested for both infections, those with increased probability of never testing for HIV/syphilis include non-gay sexual identity (prevalence odds ratio [POR] 1.86; 95% confidence interval [CI], 1.45-2.37), not disclosed their sexuality/sexual history with men other than their regular partner (POR, 2.22; 95% CI, 1.75-2.78]) or with health professionals (POR, 11.11; 95% CI, 7.69-14.29), no condomless sex with casual partners in the last 3 months (POR, 1.89; 95% CI, 1.37-2.56), no community engagement in sexual health (POR, 15.16; 95% CI, 9.40-24.45), and mainly met partners offline (POR, 1.49; 95% CI, 1.16-1.92). CONCLUSIONS: There are significant gaps in lifetime testing for HIV/syphilis among Chinese MSM. Strategies to target never testers and integrate syphilis testing within HIV testing services are urgently needed. Future opportunities include point-of-care dual test kits, and testing in China's expanding primary healthcare system

Pay-it-forward strategy to enhance uptake of dual gonorrhea and chlamydia testing among men who have sex with men in China: a pragmatic, quasi-experimental study.

BACKGROUND: Chinese men who have sex with men (MSM) rarely receive gonorrhoea and chlamydia testing. The purpose of this pilot study was to evaluate a pay-it-forward strategy to increase uptake of gonorrhoea and chlamydia testing among MSM. METHODS: We performed a quasi-experimental pragmatic study to compare a pay-it-forward model with standard of care at two HIV testing sites for MSM in Guangzhou, China: an STD clinic for MSM and a local MSM community-based organisation. All men who arrived at the STD clinic or the community-based organisation were invited to participate. In the pay-it-forward programme, men were offered free gonorrhoea and chlamydia testing and given the option of donating money toward testing for future participants. In the standard-of-care group, men were offered gonorrhoea and chlamydia testing at the standard patient price of ¥150 (about US$21·50). The pay-it-forward programme was implemented for 3 months, after which both sites switched to standard of care offering dual testing for 3 months. The primary outcome for this study was uptake of dual gonorrhoea and chlamydia testing, which we compared using χ2 test and logistic regression, reported as crude odds ratios (cOR) and adjusted odds ratios (aOR), by adjusting for nationality, marital status, income, and site of testing. FINDINGS: The pay-it-forward programme took place from Dec 2, 2017, to Feb 3, 2018, and the standard-of-care control took place from March 11, 2018, to May 1, 2018. 408 men were included in this study. 203 men were offered pay-it-forward, and 205 were offered standard of care. Overall, 109 (54%) of 203 men in the pay-it-forward group and 12 (6%) of 205 men in the standard-of-care group received gonorrhoea and chlamydia testing (cOR 18·65, 9·78-35·54; p<0·0001; aOR 19·73, 95% CI 10·02-38·85; p<0·0001). Of all 121 men who tested, this was the first gonorrhoea test for 97 (80%) men and the first chlamydia test for 104 (86%) men. Five (4%) of these 121 men were diagnosed with gonorrhoea and 15 (12%) were diagnosed with chlamydia. 97 (89%) of 109 men who received testing in the pay-it-forward group donated some money toward testing for future participants. INTERPRETATION: Pay-it-forward might be a sustainable model for expanding integrated HIV testing services among MSM in China. FUNDING: National Institutes of Health, Southern Medical University Dermatology Hospital, Doris Duke Charitable Foundation

Effect of Hyperglycemia at Presentation on Outcomes in Acute Large Artery Occlusion Patients Treated With Solitaire Stent Thrombectomy

Background: Sporadic data showed hyperglycemia at presentation is associated with poor outcomes in patients with acute ischemic stroke (AIS) under mechanical thrombectomy (MT) treatment.Objective: This study aims to evaluate the relationship of admission hyperglycemia and outcomes in patients treated with solitaire stent thrombectomy.Methods: This multicenter prospective study registered patients with AIS due to anterior circulation large vessel occlusion (LVO) suitable for MT with Solitaire stent retriever. We analyzed the influence of admission hyperglycemia (≥7.8 mmol/L) and serum glucose on functional independence which is defined as modified Rankin Scale score (mRS) of 0–2, symptomatic intracranial hemorrhage (sICH) and several outcomes of interest using univariable and multiple logistic regression analysis.Results: This study involved 17 stroke centers across China and consecutively recruited 149 patients. Patients with hyperglycemia at presentation less frequently exhibited a functional independence at 3 months than patients without hyperglycemia (22.2 vs. 66.4%; odds ratio 0.75, 95% confidence interval 0.61–0.92; P = 0.005). Higher glucose levels were correlated with worse outcome (per 1 mmol/L increase in glucose: odds ratio for mRS score 0–2 at 3 months 0.17, 95% confidence interval 0.06–0.45; P &lt; 0.001) at 3 months and sICH (per 1 mmol/L increase in glucose: odds ratio for sICH was 8.2, 95% confidence interval 1.13–29.57; P &lt; 0.001) after thrombectomy.Conclusions: Higher admission serum glucose and hyperglycemia were independently correlated with lower functional independence at 3 months in patients treated with Solitaire stent thrombectomy of anterior circulation LVO. Higher admission serum glucose was also associated with sICH after thrombectomy

Probing NaCl hydrate formation from aqueous solutions by Terahertz Time-Domain Spectroscopy

The cooling-induced formation of hydrate in aqueous NaCl solutions was probed using terahertz time-domain spectroscopy (THz-TDS). It was found that the NaCl hydrate formation is accompanied with emergence of four new absorption peaks at 1.60, 2.43, 3.34 and 3.78 THz. Combining the X-ray diffraction measurement with the solid-state based density functional theory (DFT) calculations, we assign the observed terahertz absorption peaks to the vibrational modes of the formed NaCl⋅2H2O hydrate during cooling. This work dedicates THz-TDS based analysis great potential in studying ionic hydrate and the newly revealed collective vibrational modes could be the sensitive indicators to achieve quantitative analysis in phase transitions and lattice dynamics

Safety and Efficacy of Low-Dose Tirofiban Combined With Intravenous Thrombolysis and Mechanical Thrombectomy in Acute Ischemic Stroke: A Matched-Control Analysis From a Nationwide Registry

Purpose: Tirofiban administration to acute ischemic stroke patients undergoing mechanical thrombectomy with preceding intravenous thrombolysis remains controversial. The aim of the current study was to evaluate the safety and efficacy of low-dose tirofiban during mechanical thrombectomy in patients with preceding intravenous thrombolysis.Methods: Patients with acute ischemic stroke undergoing mechanical thrombectomy and preceding intravenous thrombolysis were derived from “ANGEL-ACT,” a multicenter, prospective registry study. The patients were dichotomized into tirofiban and non-tirofiban groups based on whether tirofiban was administered. Propensity score matching was used to minimize case bias. The primary safety endpoint was symptomatic intracerebral hemorrhage (sICH), defined as an intracerebral hemorrhage (ICH) associated with clinical deterioration as determined by the Heidelberg Bleeding Classification. All ICHs and hemorrhage types were recorded. Clinical outcomes included successful recanalization, dramatic clinical improvement, functional independence, and mortality at the 3-month follow-up timepoint. Successful recanalization was defined as a modified Thrombolysis in Cerebral Ischemia score of 2b or 3. Dramatic clinical improvement at 24 h was defined as a reduction in NIH stroke score of ≥10 points compared with admission, or a score ≤1. Functional independence was defined as a Modified Rankin Scale (mRS) score of 0–2 at 3-months.Results: The study included 201 patients, 81 in the tirofiban group and 120 in the non-tirofiban group, and each group included 68 patients after propensity score matching. Of the 201 patients, 52 (25.9%) suffered ICH, 15 (7.5%) suffered sICH, and 18 (9.0%) died within 3-months. The median mRS was 3 (0–4), 99 (49.3%) achieved functional independence. There were no statistically significant differences in safety outcomes, efficacy outcomes on successful recanalization, dramatic clinical improvement, or 3-month mRS between the tirofiban and non-tirofiban groups (all p &gt; 0.05). Similar results were obtained after propensity score matching.Conclusion: In acute ischemic stroke patients who underwent mechanical thrombectomy and preceding intravenous thrombolysis, low-dose tirofiban was not associated with increased risk of sICH or ICH. Further randomized clinical trials are needed to confirm the effects of tirofiban in patients undergoing bridging therapy