Prior cocaine self-administration does not impair the ability to delay gratification in rats during diminishing returns.

Previous exposure to drugs of abuse produces impairments in studies of reversal learning, delay discounting and response inhibition tasks. While these studies contribute to the understanding of normal decision-making and how it is impaired by drugs of abuse, they do not fully capture how decision-making impacts the ability to delay gratification for greater long-term benefit. To address this issue, we used a diminishing returns task to study decision-making in rats that had previously self-administered cocaine. This task was designed to test the ability of the rat to choose to delay gratification in the short-term to obtain more reward over the course of the entire behavioral session. Rats were presented with two choices. One choice had a fixed amount of time delay needed to obtain reward [i.e. fixed delay (FD)], while the other choice had a progressive delay (PD) that started at 0 s and progressively increased by 1 s each time the PD option was selected. During the 'reset' variation of the task, rats could choose the FD option to reset the time delay associated with the PD option. Consistent with previous results, we found that prior cocaine exposure reduced rats' overall preference for the PD option in post-task reversal testing during 'no-reset' sessions, suggesting that cocaine exposure made rats more sensitive to the increasing delay of the PD option. Surprisingly, however, we found that rats that had self-administered cocaine 1-month prior, adapted behavior during 'reset' sessions by delaying gratification to obtain more reward in the long run similar to control rats.

[HVPG minimally invasive era: exploration based on forearm venous approach].

Objective: The transjugular or transfemoral approach is used as a common method for hepatic venous pressure gradient (HVPG) measurement in current practice. This study aims to confirm the safety and effectiveness of measuring HVPG via the forearm venous approach. Methods: Prospective recruitment was conducted for patients with cirrhosis who underwent HVPG measurement via the forearm venous approach at six hospitals in China and Japan from September 2020 to December 2020. Patients' clinical baseline information and HVPG measurement data were collected. The right median cubital vein or basilic vein approach for all enrolled patients was selected. The HVPG standard process was used to measure pressure. Research data were analyzed using SPSS 22.0 statistical software. Quantitative data were used to represent medians (interquartile ranges), while qualitative data were used to represent frequency and rates. The correlation between two sets of data was analyzed using Pearson correlation analysis. Results: A total of 43 cases were enrolled in this study. Of these, 41 (95.3%) successfully underwent HVPG measurement via the forearm venous approach. None of the patients had any serious complications. The median operation time for HVPG detection via forearm vein was 18.0 minutes (12.3~38.8 minutes). This study confirmed that HVPG was positively closely related to Child-Pugh score (r = 0.47, P = 0.002), albumin-bilirubin score (r = 0.37, P = 0.001), Lok index (r = 0.36, P = 0.02), liver stiffness (r = 0.58, P = 0.01), and spleen stiffness (r = 0.77, P = 0.01), while negatively correlated with albumin (r = -0.42, P = 0.006). Conclusion: The results of this multi-centre retrospective study suggest that HVPG measurement via the forearm venous approach is safe and feasible.

[Value of contrast-enhanced ultrasonography in detection of endoleak after endovascular repair of infrarenal abdominal aortic aneurysm].

Objective: To investigate the value of contrast-enhanced ultrasound in detecting endoleak after endovascular repair of infrarenal abdominal aortic aneurysm (EVAR). Methods: The postoperative follow-up data of 102 patients with infrarenal abdominal aortic aneurysm treated with EVAR in Tianjin Medical University General Hospital from August 2015 to December 2021 were retrospectively analyzed. There were 79 males and 23 females, aged 50-91 (69.6±7.6) years old. Using CT angiography (CTA) as the gold standard for diagnosing endoleaks, the effectiveness of contrast-enhanced ultrasound and CDUS in detecting endoleaks was evaluated by paired design chi-square test, and the Kappa value was calculated for consistency test. Patients were divided into groups according to body mass index (BMI), and the number of false-negative endoleaks detected by contrast-enhanced ultrasound in each group was calculated, and its ratio to the actual number of endoleaks was calculated to evaluate whether BMI was related to false-negative ultrasound-enhanced ultrasound. Results: A total of 203 follow-up visits met the inclusion criteria. Endoleaks were detected 36 times (17.7%) by CTA, 31 times (15.3%) by contrast-enhanced ultrasound, 16 times (7.9%) by CDUS, and they all detected type Ⅰ, type Ⅱ and type Ⅲ endoleaks. There was no significant difference between contrast-enhanced ultrasound and CTA in endoleak detection rate and determination of endoleak types (endoleak detection rate: 15.3% vs 17.7%; determination of endoleak types: type Ⅰ 4 vs 4, type Ⅱ 26 vs 31, type Ⅲ 1 vs 1; all P>0.05). CDUS and CTA had statistically significant differences in the detection rate of endoleaks and determination of endoleak types (endoleak detection rate: 7.9% vs 17.7%; determination of endoleak types: type Ⅰ 4 vs 4, type Ⅱ 11 vs 31, type Ⅲ 1 vs 1; all P<0.001). Compared with CTA, contrast-enhanced ultrasound has a sensitivity of 83.3%, a specificity of 99.4%, a Youden index of 0.827, a coincidence rate of 96.6%, a positive predictive value of 96.8%, a negative predictive value of 96.5%, and a Kappa value of 0.875(P<0.001). The two showed excellent diagnostic consistency. All 6 endoleaks not detected by contrast-enhanced ultrasound were type Ⅱ endoleak that did not require treatment, and 3(15.8%) occurred in obese patients with a BMI≥32 kg/m2. Compared with CTA, CDUS had a sensitivity of 38.9%, a specificity of 98.8%, a Youden index of 0.377, a coincidence rate of 88.2%, a positive predictive value of 87.5%, a negative predictive value of 88.2%, and a Kappa value of 0.482 (P<0.001). The two showed moderate diagnostic agreement. The correlation coefficient of the maximum diameter of aneurysms measured by ultrasound and CT was r=0.873(P<0.001). Conclusions: Contrast-enhanced ultrasound is accurate in detecting endoleak after infrarenal EVAR, and its sensitivity to endoleak detection in obese patients with BMI≥32 kg/m2 will be reduced. CDUS is not suitable for detection of endoleak after infrarenal EVAR, but it can be used to monitor the change of the largest diameter of aneurysm after EVAR.

Prevalence and potential risk factors of chronic pruritus among community middle-aged and older population in Beijing, China.

BACKGROUND: Chronic pruritus is a common problem among older adults, with a significant impact on their quality of life. However, it is under-studied epidemiologically, especially among Chinese older adults. OBJECTIVE: The aim of this study was to identify the prevalence and explore the risk factors of chronic pruritus among the middle-aged and older adults in Beijing, China. METHODS: A total of 929 participants aged ≥35 years from six communities in Beijing, China, were interviewed. The survey collected the demographic characteristics, the experience of chronic pruritus (>6 weeks), chronic disease history, the level of physical activities and sleep quality. A population-based case-control study was conducted, including 178 chronic pruritus cases and 697 controls. A multivariate logistic regression model was performed to explore the risk factors of chronic pruritus. Additionally, a random forest algorithm was used to rank the importance of potential risk factors and analyse the overall interpretation of risk factors. RESULTS: The prevalence of chronic pruritus was 19.48% (181/929) among the Beijing middle-aged and elderly population. The findings indicated that older adults aged 65 years old or above, male, with college or higher degree, alcohol drinking, hypertension, hyperlipidaemia, chronic lung disease, cardiovascular disease, digestive system disease and osteoarthritis/rheumatism, and middle or low sleep quality were associated with the increased risk of chronic pruritus respectively. Physical activity level (≥3000 Met) was associated with a decreased risk of chronic pruritus. The rank according to the most contribution of chronic pruritus risk was sleep quality, education, physical activity level, osteoarthritis/rheumatism, age and gender. CONCLUSION: Prevalence of chronic pruritus was high among the Chinese middle-aged and elderly population. Age, gender, high education, alcohol drinking, hypertension, hyperlipidaemia, chronic lung disease, cardiovascular disease, digestive system disease, osteoarthritis /rheumatism and poor sleep quality may serve as risk factors of chronic pruritus. Moderate and high physical activity levels may serve as protective factors of chronic pruritus risk.

[Significance of molecular classification in fertility-sparing treatment of endometrial carcinoma and atypical endometrial hyperplasia].

Objective: To investigate the molecular classification of endometrial carcinoma (EC) and atypical endometrial hyperplasia (AEH) treated with fertility-sparing therapy, and to analyze its relationship with clinicopathological factors and treatment efficacy. Methods: A total of 46 EC and AEH patients who received fertility-sparing therapy and molecular classification tested by next generation sequencing in Peking University People's Hospital from June 2020 to December 2021, were retrospectively collected. The relationships between molecular classification and clinicopathological factors and treatment outcomes were analyzed. Results: (1) Of the 46 patients, including 40 EC and 6 AEH patients, 32 cases (71%, 32/45) had complete response (CR) after treatment, with median CR time of 8 months, 6 cases (13%, 6/45) had partial response, and 8 cases (25%, 8/32) had recurrence. (2) The cases were distributed as no specific molecular profile (NSMP) 34 cases (74%, 34/46) subtype mainly, high microsatellite instability (MSI-H) 7 cases (15%, 7/46), POLE ultra-mutated 3 cases (7%, 3/46), and copy number high (CNH) 2 cases (4%, 2/46). Patients with CNH had the hightest serum cancer antigen 125 (CA125) level [(34.3±35.2) kU/L]. MSI-H subtype had more family history of tumors (6/7), more with loss of mismatch repair (MMR) protein expression by immunohistochemical (7/7), and higher nuclear antigen associated with cell proliferation (Ki-67) expression level (3/3). (3) Patients in MSI-H subgroup had the lowest CR rate at 6 months (0/6; P=0.019), and survival analysis showed that they were less likely to achieve CR than those with NSMP subtype (P=0.022). Subgroup analysis of patients with NSMP showed that age ≥30 years related with longer treatment time to CR (P=0.010). In addition, CR was obtained after treatment in 2/3 POLE ultra-mutated cases and 2/2 CNH, respectively. Conclusions: Molecular classification relates with the treatment response in patients with EC and AEH treated with fertility-sparing therapy. Patients with MSI-H subtype have poor treatment efficacy, and patients with NSMP need to be further studied and predict treatment benefit. However, there are few cases in POLE ultra-mutated and CNH subtypes, which need further clinical research.

[Clinical outcomes of simultaneous bilateral endoscopic surgery for bilateral upper urinary tract calculi].

OBJECTIVE: To discuss the efficacy and safety of simultaneous bilateral endoscopic surgery (SBES) for bilateral upper urinary tract calculi, and to summarize the initial experience. METHODS: Patients diagnosed with bilateral upper urinary tract calculi who underwent SBES in the Department of Urology, Beijing Chao-Yang Hospital from January 2019 to January 2020 were enrolled retrospectively. The demographic and clinical data of the patients were recorded, and the operation status, stone free rate (SFR) and peri-operative complications were analyzed. The primary end point was SFR, and second end point was peri-operative complications. RESULTS: A total of 23 patients underwent SBES, of which SBES was completed in 19 patients (12 males, and 7 females). The mean age was (41.3±12.0) years. Fourteen patients underwent modified supine position surgery and 4 patients in prone split-leg position. There was no statistical difference in the demographic and baseline clinical data of the patients in different positions. One patient underwent right percutaneous nephrolithotomy (PCNL) and left endoscopic combined intra-renal surgery (ECIRS) in the prone split-leg position, while 18 patients received simul-taneous surgery with PCNL and contralateral retrograde intra-renal surgery (RIRS). The mean anesthesia and operation time was (128.7±26.5) min and (70.7±20.3) min, respectively, which was significantly longer in the patients with prone split-leg position than in the patients with modified supine position, anesthesia time in the patients with prone split-leg position and modified supine position: (148.4±20.4) min vs. (121.6±25.3) min, respectively, t=－2.121, P=0.049, while the operation time in the patients with prone split-leg position and modified supine position: (86.4±21.1) min vs. (65.1±17.4) min, respectively, t=－2.222, P=0.040. There was no significant difference between the two groups in indwelling of nephrostomy [prone split-leg position and modified supine position: (2.6±0.9) d vs. (2.1±1.0) d, respectively; t=－0.880, P=0.391] and the length of hospital stay [prone split-leg position and modified supine position: (6.0±2.7) d vs. (5.2±1.8) d, respectively; t=－0.731, P=0.475]. One month after the operation, the SFR was 78.9%, and 3 patients had minor peri-operative complications (Clavien-Dindo grades Ⅰ/Ⅱ) without any serious complications (Clavien-Dindo grades Ⅲ/Ⅳ/Ⅴ). CONCLUSION: The simultaneous bilateral endoscopic surgery would decrease the operation time and anesthesia exposure under the premise of ensuring the SFR, which is helpful to reduce the risk of peri-operative complications, especially to the patients who can not tolerate the second-stage or long-time operation.

[Endoscopic combined ultrasound-guided access vs. ultrasound-guided access in endoscopic combined intrarenal surgery].

OBJECTIVE: To compare the outcomes of endoscopic combined ultrasound-guided access (EUGA) with the conventional ultrasound-guided access (UGA) to achieve percutaneous renal access in endoscopic combined intrarenal surgery (ECIRS). METHODS: A retrospective review of 53 patients undergoing ECIRS to treat upper urinary tract calculi between January 2017 and October 2019 was con-ducted. All of the cases were of complex upper urinary tract stones larger than 2 cm in diameter. The com-plex stone situations, such as multiple renal calyces calculi or staghorn calculi necessitated ECIRS. Under general anesthesia, the patients were placed in the galdakao-modified supine valdivia (GMSV) position, thus allowing both antegrade and retrograde accesss. The patients were divided to UGA and EUGA groups according to the protocol of achieving percutaneous renal access. In 28 cases, endoscopic combined ultrasound-guided accesss were obtained. Puncture and dilation were performed under direct flexible ureteroscopic visualization, while percutaneous renal access of 25 cases were performed with the conventional technique employing ultrasound guidance. Demographic and perioperative information, such as stone burden, presence of hydronephrosis and number of calyces involved was compared. Primary outcomes included total operative time, renal access time, repeat puncture, hemoglobin level, perioperative complications, and stone-free rate. RESULTS: No major intra-operative complication was recorded in all the 53 ECRIS. No significant difference was observed between the groups in age and gender. There was no significant difference in body mass index[BMI (29.21±3.14) kg/m2 vs.(28.53±2.56) kg/m2], stone burden (37.68±6.89) mm vs. (35.53±6.52) mm, number of calyces involved 2.72±0.68 vs. 2.86±0.71, presence of hydronephrosis (56.0% vs. 46.4%), total operative time (93.0±12.2) min vs. (96.8±14.2) min, hemoglobin level reduction (6.56±2.16) g/L vs. 97.54±2.64) g/L, stone-free rate (92.0% vs. 92.8%), hospital stay (5.52±0.59) d vs. (5.64±0.62) d, perioperative complication rate (8.0% vs. 7.2%). Two patients in EUGA group experienced perioperative complications (one urinary tract infection and one hematuria) while two patients in UGA group experienced perioperative urinary tract infection. None in both groups received blood transfusion. The patients undergoing EUGA had shorter renal access time [(4.0±0.7) min vs. (6.8±2.6) min, P < 0.01] and less repeat puncture (0 vs. 4 cases, P < 0.05). CONCLUSION: EUGA is an optimal technique to establish percutaneous renal access in ECIRS, which minimizes access time and repeated procedures.

[Current situation of screening, prevention and treatment of bleeding esophageal varices in cirrhotic portal hypertension in Tibet region: a multicenter study].

Objective: To investigate and analyze the current situation, screening, clinical characteristics, prevention and treatment of bleeding esophageal varices in cirrhotic patients with portal hypertension in Tibet region. Methods: Clinical data of cirrhotic patients with portal hypertension through March 2017 to February 2020 from Tibet region were collected and analyzed retrospectively. Results: 511 cases with liver cirrhosis were included in the study, of which 185 cases (36.20%) had compensated cirrhosis and 326 cases (63.80%) had decompensated cirrhosis. Further analysis of the etiological data of liver cirrhosis showed that 306 cases (59.88%) were of chronic hepatitis B, 113 cases (22.11%) of alcoholic liver disease, and 68 cases (13.31%) of chronic hepatitis B combined with alcoholic liver disease. Among patients with compensated liver cirrhosis, 48 cases (25.95%) underwent endoscopic examination of which 33 diagnosed as high-risk variceal bleeding. However, none of these 33 cases had received non-selective ß-blocker therapy, and only four patients had received endoscopic variceal banding therapy. Among patients with decompensated liver cirrhosis, 83 cases (25.46%) had a history of upper gastrointestinal bleeding, 297 cases (91.10%) had ascites, 23 cases (7.05%) had hepatic encephalopathy, and 3 cases (0.92%) had hepatorenal syndrome. Among the patients with a history of upper gastrointestinal bleeding, 42 cases (50.60%) had received secondary preventive treatment for bleeding esophageal varices, including 39 cases of endoscopic treatment, 1 case of endoscopic combined drug treatment, 3 cases of interventional treatment, and 2 cases of surgical treatment. Conclusion: Chronic hepatitis B and alcoholic liver diseases are the main causes of liver cirrhosis in Tibet region. Moreover, this region lacks screening, prevention and treatment for bleeding esophageal varices in cirrhotic patients with portal hypertension. Therefore, it is necessary to increase the screening of high-risk groups to prevent and improve the first-time bleeding, and promote multidisciplinary team to prevent and treat re-bleeding.

[The role of three-dimensional speckle tracking imaging derived parameters on predicting outcome of hypertrophic cardiomyopathy patients with MYH7 mutations].

Objective: To evaluate the cardiac functional changes in hypertrophic cardiomyopathy(HCM) patients with ß-myosin heavy chain gene (MYH7) mutations by three-dimensional (3D) speckle tracking imaging(3D-STI) and conventional echocardiography modalities, and then to explore the potential predictors of adverse cardiovascular events in these patients. Methods: A consecutive series of 192 HCM patients admitted in our center from October 2014 to October 2016 were genetically screened to identify MYH7 mutations in this retrospective study. A total of 43 HCM patients with MYH7 mutations were enrolled. The patients were divided into events group(n=13) and no event group(n=30) according to the presence or absence of adverse cardiovascular events(primary and secondary endpoints). All patients were followed up to January 2019 after comprehensive evaluation of 3D-STI, two-dimensional and Doppler echocardiography. The adverse cardiovascular events were recorded. Results: The median follow up time was 1 012 (812, 1 330) days. During follow-up, 13 patients (30.2%) reached endpoints: 6 cases of the primary endpoints(2 cases of sudden cardiac death(SCD), 3 cases of survival after defibrillation, and 1 case of appropriate implantable cardioverter-defibrillator(ICD) discharge); 7 cases of the second endpoints(5 cases of heart failure hospitalization, 1 case of syncope and cardioversion due to supraventricular tachycardia, and 1 case of end-stage HCM). Patients with adverse cardiovascular events had higher prevalence of syncope and risk of SCD, enlarged left atrial volume index(LAVI) and reduced 3D left ventricular global longitudinal train (3D-GLS), as compared to those without adverse events(all P<0.05). The multivariate Cox regression analysis showed that reduced 3D-GLS(HR=0.814, 95%CI 0.663-0.999, P=0.049) was an independent predictor for adverse cardiovascular events. The cutoff value of 3D-GLS≤13.67% was linked with significantly increased risk of adverse cardiovascular events in this patient cohort(AUC=0.753, 95%CI 0.558-0.948, sensitivity 86%, specificity 69%, P<0.05). The Kaplan-Meier analysis indicated that the patients with the 3D-GLS≤ 13.67% faced higher risk of death than those with 3D-GLS>13.67%. Conclusion: 3D-GLS is useful on predicting adverse cardiovascular events in HCM patients with MYH7 mutations.

Crossover from Coulomb blockade to ballistic transport in InAs nanowire devices.

We report on the observation of a crossover from the single electron Coulomb blockade regime to the ballistic transport in individual InAs semiconducting nanowire devices. The InAs nanowires studied here were grown by molecular-beam epitaxy (MBE), which provides a clean system to study the intrinsic electrons transport in a quasi-one-dimensional system. Quantized conductance plateaus are observed for an InAs nanowire-based device by changing the Fermi level with a global back gate at low temperature, suggesting the ballistic transport of electrons. Further lowering the temperature, we observe the Coulomb blockade phenomenon with the formation of the quantum dot between the two normal metal contacts. By increasing the electron density, the characteristic Fabry-Pérot oscillations are observed, which further provides evidence for the ballistic nature of transport in the InAs nanowire device. Our observations indicate that high-quality InAs nanowires grown by MBE behave as clean quantum wires at low temperatures, which enables us to investigate novel phenomena in the quasi-one-dimensional system.

Symbiotic fungal endophyte Phomopsis liquidambari-rice system promotes nitrogen transformation by influencing below-ground straw decomposition in paddy soil.

AIMS: To explore if and how symbiotic Phomopsis liquidambari-rice system influences below-ground straw decomposition and then nitrogen(N) transformation in response to environmental N levels. METHODS AND RESULTS: Litter bag experiments were utilized to trace the decay process during rice growth phases (seedling (T1), tillering (T2), heading (T3) and maturing (T4) stage), with (E+) and without endophyte (E-), under low (LN), medium (MN) and high nitrogen (HN) supply. Litter, soil and plant samples were collected to evaluate the decay process, N transformations, plant quality and relative abundance of soil ammonia-oxidizing archaea (AOA), ammonia-oxidizing bacteria (AOB) and P. liquidambari. The results showed that straw decomposition increased by 19·76% (LN, T2 stage), 14·05% (MN, T3 stage) and 16·88% (MN, T4 stage) in E+ pots when compared with E- pots. Further analysis revealed that no significant endophyte × N interaction was found for straw decay rate and that the decay rate was reduced by a higher N supply (LN, 37·16 ± 0·65%; MN, 32·27 ± 1·72%; HN, 29·44 ± 1·22%) at the T1 stage, whereas straw decay rate and N release increased by 9·38 and 11·16%, respectively, mainly by endophyte colonization at the T4 stage. The abundance of AOA and AOB were altered, corresponding with the decay rate. Soil mineral N, straw mineral N and plant quality were shown to increase in E+ pots, depending on environmental N conditions and growth phase. The yield increased by 2·98% for E+ plants under MN level. CONCLUSIONS: Symbiotic P. liquidambari-rice system promoted below-ground straw decomposition and N transformation, depending on environmental N levels and plant growth phase. SIGNIFICANCE AND IMPACT OF THE STUDY: This study provides evidence that fungal endophyte-plant systems are able to promote N transformation by increasing straw decomposition. A reasonable combination of N inputs could enhance its advantage in agriculture ecosystems.

[Effects of occupational noise exposure on asymmetric hearing loss in automobile manufacturing workers].

Objective: To investigate the characteristics of asymmetric hearing loss in automobile manufacturing workers and the effect of occupational noise exposure on asymmetric hearing loss. Methods: A cross-sectional approach was used in this study. From March 2017 to February 2018, Subjects (7066) from four complete vehicle factories were given a pure tone audiometry (Hearing thresholds were measured at frequencies of 0.5, 1, 2, 3, 4 and 6 kHz in each ear) and were required to complete a health-related information questionnaire. According to the inclusion criteria, a total of 6339 workers were selected. The mean hearing thresholds for the left and right ears at overall frequencies were compared using the repeated means analysis of variance (ANOVA) test. The threshold differences at each frequency were compared using paired t tests. Results: The overall mean left minus right threshold difference across all frequencies was determined to be 0.58 dB, which met statistical significance (P<0.01) . Hearing threshold in the left ear was statistically significantly higher compared with the right ear at each frequency. The differences between binaural threshold shifts at each frequency among subjects with a asymmetry in terms of worse left ear and worse right ear were at the range of 6.17-9.87 dB and 6.39-10.92 dB, respectively. Hearing threshold in the left ear was statistically significantly higher compared with the right ear at only 2, 3 kHz of subjects with high-frequency hearing threshold shifts (HFHTs) more than 25 dB. Hearing threshold in the left ear was statistically significantly higher compared with the right ear at only 3 kHz of subjects with high-frequency hearing threshold shifts (HFHTs) more than 30 dB. With the increase of HFHTs, the proportion of subjects with a asymmetry at 2 and 3 kHz of more than 10 dB in terms of worse left ear and worse right ear increased. Conclusion: The average hearing threshold of the left ear across overall frequencies is higher compared with the right ear, the proportion of the cases with a higher left ear hearing threshold is higher that that of the cases with a higher right ear hearing threshold. As hearing loss caused by occupational noise exposure getting worse, the proportion of the cases with a higher left ear hearing threshold and the cases with a higher right ear hearing threshold may tent to be the same.

Low-field magnetotransport in graphene cavity devices.

Confinement and edge structures are known to play significant roles in the electronic and transport properties of two-dimensional materials. Here, we report on low-temperature magnetotransport measurements of lithographically patterned graphene cavity nanodevices. It is found that the evolution of the low-field magnetoconductance characteristics with varying carrier density exhibits different behaviors in graphene cavity and bulk graphene devices. In the graphene cavity devices, we observed that intravalley scattering becomes dominant as the Fermi level gets close to the Dirac point. We associate this enhanced intravalley scattering to the effect of charge inhomogeneities and edge disorder in the confined graphene nanostructures. We also observed that the dephasing rate of carriers in the cavity devices follows a parabolic temperature dependence, indicating that the direct Coulomb interaction scattering mechanism governs the dephasing at low temperatures. Our results demonstrate the importance of confinement in carrier transport in graphene nanostructure devices.

Optical clearing agent reduces scattering of light by the stratum corneum and modulates the physical properties of coenocytes via hydration.

BACKGROUND: The interaction between light and the skin determine how the skin looks to the human eye. Light can be absorbed, scattered, and reflected by different components of the skin in a variety of different ways. Here, we focus on the scattering properties of the outmost layer, the stratum corneum (SC). However, we currently have limited methods with which to distinguish the scattering of light by SC from the changes due to other components of the skin. MATERIALS AND METHODS: Dark-field images of tape-striped corneocytes were used in vitro to study the differences in light scattered by the SC and other skin components. Several optical clearing agents (OCAs) were tested for their ability to reduce light scattering. Physical properties of the SC (water content, keratin configuration, and volume) after OCA treatment were investigated using FT-IR, confocal Raman microscopy, and 3D laser microscopy. RESULTS: Urea derivatives, several reducing sugars, and sugar alcohols, which were used as OCA in optics and also used as humectants in cosmetic area, could reduce scattering. However, unlike dehydration in optics, penetration of water into the keratin was increased at low OCA concentrations. In such conditions, the volume of corneocytes was increased but their stiffness was reduced. CONCLUSION: By analyzing the tape-striped SC, we were able to measure the changes in the optical and physical properties of corneocytes in response to OCAs. Hydration of the SC layer by OCAs reduces light scattering from the corneocytes and would be helpful in moisturizing the skin and helping the skin look healthy.

[Occupational health risk assessment of coal dust in coal industry chain].

Objective: To grasp the present situation of occupational hazards of coal dust in our country, understand our country coal dust workers' occupational health risks, provide information based on evidence and analysis for the government and organize to effectively deal with the current status of high coal workers pneumoconiosis incidence in China, and protect coal dust workers' occupational health. Methods: The research object is the " mining-transportation-use" of coal industrial chain, referring to 33 units. Use field investigation to obtain the coal dust exposure, dust prevention measures and the occupational health data of study object. Use quantitative evaluation method of International council on mining and metals occupational health risk assessment model (ICMM method) and occupational hazard risk index method (index method) , with coal workers pneumoconiosis as health outcomes, to evaluate the coal dust occupational health risks of coal industrial chain. Results: The free silica content of partial coal dust in China is more than 10%, and even to 19.5%. coal dust concentration in workplaces, such as excavating system of dust coal mining (total dust: 22.1~46.5 mg/m(3), respiratory dust: 8.4~17.7 mg/m(3)) , dumper (total dust: 25.2 mg/m(3), respiratory dust: 6.9 mg/m(3)) , transfer tower (total dust: 35.4 mg/m(3)) of coal transportation and belt coal plough device of coal use (total dust: 36.3 mg/m(3), respiratory dust: 14.0 mg/m(3)) , are much higher than those in other workplaces, and coal dust concentration of workers in these places (2.6~9.3 mg/m(3)) are much higher than those in other places, which are statistically significant. ICMM method evaluation results show that the risk value of excavating system is between 504~1 089, and the risk value of comprehensive mining system is between 347~2 040, which are far statistically significant higher than that of other systems. Index method evaluation results (excavating system risk value between 3.1~9.7, fully mechanized system risk value between 3.7~9.3) , are basically identical with ICMM method (correlation coefficient r=0.857, P<0.01) . The new cases of coal worker pneumoconiosis are distributed in three post of coal mining, excavating and coal mine mixing. Conclusion: Coal-dust hazards are widely distributed in the coal "mining, transportation, and use" industrial chain, which of the underground coal mine is as serious as intolerable, meanwhile the risk of other industrial chain is basically can tolerable. The high coal dust concentration and the high risk of coal dust occupational hazard are concentrated in the excavating system and the comprehensive mining system. It is recommended to start the study on risk assessment and risk response of coal dust health hazard at the national level, and the occupational exposure limit of coal dust should be established according to the content of free silica.

Measurements of scar properties by SkinFibroMeter® , SkinGlossMeter® , and Mexameter® and comparison with Vancouver Scar Scale.

BACKGROUND: An objective measurement of scar is important for evaluating treatment outcomes. However, to date, there is no 'gold standard' for quantitative measurement of properties of hypertrophic scar. Existing objective modalities are neither portable nor easy to use. OBJECTIVE: This study aims to validate the correlation between objective measurements with SkinFibrometer® , SkinGlossMeter® , and Mexameter® and subjective assessment with Vancouver Scar Scale (VSS) of keloid and hypertrophic scar. METHODS: A total of 25 patients with keloids and hypertrophic scars were enrolled in this study. Patients were treated with intralesional triamcinolone acetonide at 2-6 week intervals. Scar assessments using VSS, Skinfibrometer, Skinglossmeter, and Mexameter were performed in both scars and contralateral normal skin at each treatment session. Correlations between the measurements by these tools and VSS parameters were examined. RESULTS: We found statistically significant differences between scar and contralateral normal skin using Skinfibrometer, Skinglossmeter, and Mexameter. A strong correlation was found between the VSS pliability scores and the stiffness of skin of Skinfibrometer (r = 0.628, P < 0.001). VSS vascularity scores showed weak correlation with erythema index of Mexameter (r = 0.372, P < 0.001). However, no correlation appeared to exist between any parameters of VSS and Skinglossmeter and between VSS pigmentation scores and the melanin index of Mexameter. CONCLUSION: In our study, Skinfibrometer can be an objective noninvasive evaluation tool for pliability of the scar.

Free-Standing Two-Dimensional Single-Crystalline InSb Nanosheets.

Growth of high-quality single-crystalline InSb layers remains challenging in material science. Such layered InSb materials are highly desired for searching for and manipulation of Majorana Fermions in solid state, a fundamental research task in physics today, and for development of novel high-speed nanoelectronic and infrared optoelectronic devices. Here, we report on a new route toward growth of single-crystalline, layered InSb materials. We demonstrate the successful growth of free-standing, two-dimensional InSb nanosheets on one-dimensional InAs nanowires by molecular-beam epitaxy. The grown InSb nanosheets are pure zinc-blende single crystals. The length and width of the InSb nanosheets are up to several micrometers and the thickness is down to ∼10 nm. The InSb nanosheets show a clear ambipolar behavior and a high electron mobility. Our work will open up new technology routes toward the development of InSb-based devices for applications in nanoelectronics, optoelectronics, and quantum electronics and for the study of fundamental physical phenomena.

[Topping-off surgery versus double-segment fusion for treatment of lumbar degenerative disease with mid-long term follow-up].

Objective: To compare the mid-long term clinical effect of Topping-off surgery and lumbar fusion surgery for two-segmental lumbar degenerative disease. Methods: From March 2009 to March 2012, one hundred and twenty-six consecutive patients (Topping-off surgery and two-segment PLIF surgery) were studied in Orthopedics Department, Beijing Chao-Yang Hospital, Capital Medical University.The VAS and ODI were used to assess clinical symptoms.All patients underwent flexion/extension radiographs examinations before surgery, 1, 2 years and last follow-up postoperatively.Lumbar lordosis, sacral slop, data of Coflex segment and adjacent segment (disc height index, range of motion, foraminal height, foraminal width and Pfirrmann classification of intervertebral disc in MRI) were recorded.The paired double-tailed t test was used to analyze the differences in the results from baseline to each postoperative time point.The paired double-tailed t test was used in both groups to analyze the differences in the results from baseline to each postoperative time point.The Chi-square test was used to evaluate the differences between the incidences of adjacent segment degeneration(ASD) in the groups. Logistic regression analysis was used to analyze risk factors for developing radiographic ASD. Results: In topping-off group, 60 patients, average operation time was (134.5±10.2) min. The average blood loss was (301.5±64.6) ml.In fusion group, 68 patients, average age (58.3±4.6) years.The average follow-up time was (47.5±5.1) months.The average operation time was (158.6±19.3) min (P=0.000). The average blood loss was (413.6±131.3) ml (P=0.000). Sex, age, body mass index and intervertebral disc grading were matched between the two groups.Better improvement in VAS back pain score was noted in the topping-off group over the fusion group (P=0.030). Both groups achieved good recovery in ODI and improvement in VAS leg pain and back pain scores at last follow-up postoperatively.In the Topping-off group, FH increased from 10.5 mm at baseline to 11.8 mm at 1 year after surgery (P=0.000) and then decreased mildly in the third postoperative year, while in the fusion group, showed no significant change at all postoperative time points.In the fusion group, the disc height and FW at the same segment were no significant change after first year follow-up, while ROM was significantly decreased after surgery (P=0.000). Foraminal height, foraminal width and intervertebral disc height of adjacent segment of Coflex implant level were found decreased at the end of the postoperative follow-up, while compared with preoperative data no significant difference (P>0.05). At last follow-up, eight patients (13.3%) in the Topping-off group and eighteen patients (26.5%) in the fusion group developed ASD (P=0.033). Conclusions: Topping-off surgery compared with two-segment lumbar fusion surgery can achieve a good result in cases with pre-existing mild or moderate adjacent segment degeneration, restrict the adjacent segment's range of motion and reduce the adjacent segment degeneration. Under strict indications, Topping-off surgery is an acceptable alternative to fusion surgery for the treatment of two-segment lumbar disease.

[Predicting value of 2014 European guidelines risk prediction model for sudden cardiac death (HCM Risk-SCD) in Chinese patients with hypertrophic cardiomyopathy].

Objective: To evaluate the predicting value of the 2014 European Society of Cardiology (ESC) guidelines risk prediction model for sudden cardiac death (HCM Risk-SCD) in Chinese patients with hypertrophic cardiomyopathy (HCM), and to explore the predictors of adverse cardiovascular events in Chinese HCM patients. Methods: The study population consisted of a consecutive 207 HCM patients admitted in our center from October 2014 to October 2016. All patients were followed up to March 2017. The 5-year SCD probability of each patient was estimated using HCM Risk-SCD model based on electrocardiogram, echocardiography and cardiac magnetic resonance (CMR) examination results. The primary, second, and composite endpoints were recorded. The primary endpoint included SCD and appropriate ICD therapy, identical to the HCM Risk-SCD endpoint. The second endpoint included acute myocardial infarction, hospitalization for heart failure, thrombus embolism and end-stage HCM. The composite endpoint was either the primary or the second endpoint. Patients were divided into the 3 categories according to 5-year SCD probability assessed by HCM Risk-SCD model: low risk group<4%,intermediate risk group ≥4% to<6%, and high risk group≥6%. Results: (1) Prevalence of endpoints: All 207 HCM patients completed the follow-up (350 (230, 547) days). During follow-up, 8 (3.86%) patients reached the primary endpoints (3 cases of SCD, 3 cases of survival after defibrillation, and 2 cases of appropriate ICD discharge); 21 (10.14%) patients reached the second endpoints (1 case of acute myocardial infarction, 16 cases of heart failure hospitalization, 2 cases of thromboembolism, and 2 cases of end-stage HCM). (2) Predicting value of HCM Risk-SCD model: Patients with primary endpoints had higher prevalence of syncope and intermediate-high risk of 5-year SCD, as compared to those without primary endpoints (both P<0.05). (3) Predicting value of HCM Risk-SCD model: The low risk group included 122 patients (59%), the intermediate risk group 42 (20%), and the high risk group 43 (21%). There was a clear trend towards to higher heart rate, higher values of PTF(V1) and plane QRS-T angle, higher left ventricular mass index (LVMI), elevated maximal left ventricular outflow tract pressure gradient (LVOT-PGmax), enlarged left atrial dimension(LAD) and volume index (LAVI), reduced systolic mitral annular velocity (s'), and higher late gadolinium enhancement (LGE) volume and mass in patients with high risk of 5-year of SCD, as compared to those with low-intermediate risk (all P<0.05). Moreover, 5-year SCD probability was positively correlated with heart rate, plane QRS-T angle, LVMI, LAVI, LGE%, and negatively correlated with s'(r=0.161, P=0.019; r=0.669, P=0.001; r=0.206, P=0.004; r=0.284, P=0.000; r=0.351, P=0.000; r= -0.245, P=0.001; respectively). (4) LAD, LAVI, e' and s' were independent predictors for poor outcomes. HCM patients with LAD≥39 mm, LAVI≥49.6 ml/m(2), e'≤6.5 cm/s and s'≤6.6 cm/s were more likely to have adverse cardiovascular events (AUC 0.702, 95%CI 0.604-0.799, P=0.001; AUC 0.700, 95%CI 0.567-0.833, P=0.001; AUC 0.716, 95%CI 0.616-0.817, P=0.000; AUC 0.764, 95%CI 0.676-0.853, P=0.000,respectively). Conclusions: The HCM Risk-SCD model is of value in predicting SCD for Chinese HCM patients. The plane QRS-T angle and LGE% are the best predictors of 5-year SCD risk in Chinese HCM patients. Moreover, conventional echocardiographic parameters, including LAD, LAVI, e' and s', are useful to predict adverse cardiovascular events among Chinese HCM patients.

Schottky barrier and contact resistance of InSb nanowire field-effect transistors.

Understanding of the electrical contact properties of semiconductor nanowire (NW) field-effect transistors (FETs) plays a crucial role in the use of semiconducting NWs as building blocks for future nanoelectronic devices and in the study of fundamental physics problems. Here, we report on a study of the contact properties of Ti/Au, a widely used contact metal combination, when contacting individual InSb NWs via both two-probe and four-probe transport measurements. We show that a Schottky barrier of height [Formula: see text] is present at the metal-InSb NW interfaces and its effective height is gate-tunable. The contact resistance ([Formula: see text]) in the InSb NWFETs is also analyzed by magnetotransport measurements at low temperatures. It is found that [Formula: see text] in the on-state exhibits a pronounced magnetic field-dependent feature, namely it is increased strongly with increasing magnetic field after an onset field [Formula: see text]. A qualitative picture that takes into account magnetic depopulation of subbands in the NWs is provided to explain the observation. Our results provide solid experimental evidence for the presence of a Schottky barrier at Ti/Au-InSb NW interfaces and can be used as a basis for design and fabrication of novel InSb NW-based nanoelectronic devices and quantum devices.