Phosphorus-doped synergy of phase change in heterogeneous catalysts of NiS-NiS2 for efficient electrocatalysis of Pb(II).

A fundamental understanding of the electroanalytical activity of transition metal sulfide electrocatalysts, especially the origin of the electrocatalytic reactivity on the surface sites of heterostructures with multiple crystalline phases, is essential for the design of low-cost and highly efficient nonprecious metal electrocatalysts for further scientific and technological achievements. Herein, we injected P into NiS and occupied the S sites through a doping strategy. The redistributed electronic structure induced the construction of heterostructures, which significantly improved the structure and chemical state of electrochemically inert NiS. The phase-change mechanism between NiS and NiS2 synergistically catalyzes Pb(II), while the P and S sites jointly lose electrons. Moreover, the constructed heterojunction sensor shows the a sensitivity of 83.43 µA µM-1 to Pb(II) with a theoretical limit of detection of 48 nM, as well as excellent stability, reproducibility, and anti-interference ability. The accurate detection in real water further reveals the potential of this sensor for practical applications. This study provides a guiding strategy for improving electrochemically inert materials to design highly active electrocatalytic interfaces, which has important implications for the development of highly efficient electrode-sensitive materials similar to precious metals to achieve accurate electrical analysis.

Cholinergic neurons in the pedunculopontine nucleus guide reversal learning by signaling the changing reward contingency.

Cognitive flexibility enables effective switching between mental processes to generate appropriate responses. Cholinergic neurons (CNs) within the pedunculopontine nucleus (PPN) are associated with many functions, but their contribution to cognitive flexibility remains poorly understood. Here we measure PPN cholinergic activities using calcium indicators during the attentional set-shifting task. We find that PPN CNs exhibit increasing activities correlated with rewards during each stage and error trials in reversal stages, indicating sensitivity to rule switching. Inhibition of PPN cholinergic activity selectively impairs reversal learning, which improves with PPN CN activation. Activation of PPN CNs projecting to the substantia nigra pars compacta, mediodorsal thalamus, and parafascicular nucleus in a time-locked manner with reward improves reversal learning. Therefore, PPN CNs may encode not only reward signals but also the information of changing reward contingency that contributes to guiding reversal learning through output projections to multiple nuclei that participate in flexibility.

Parabrachial nucleus circuit governs neuropathic pain-like behavior.

The lateral parabrachial nucleus (LPBN) is known to relay noxious information to the amygdala for processing affective responses. However, it is unclear whether the LPBN actively processes neuropathic pain characterized by persistent hyperalgesia with aversive emotional responses. Here we report that neuropathic pain-like hypersensitivity induced by common peroneal nerve (CPN) ligation increases nociceptive stimulation-induced responses in glutamatergic LPBN neurons. Optogenetic activation of GABAergic LPBN neurons does not affect basal nociception, but alleviates neuropathic pain-like behavior. Optogenetic activation of glutamatergic or inhibition of GABAergic LPBN neurons induces neuropathic pain-like behavior in naïve mice. Inhibition of glutamatergic LPBN neurons alleviates both basal nociception and neuropathic pain-like hypersensitivity. Repetitive pharmacogenetic activation of glutamatergic or GABAergic LPBN neurons respectively mimics or prevents the development of CPN ligation-induced neuropathic pain-like hypersensitivity. These findings indicate that a delicate balance between excitatory and inhibitory LPBN neuronal activity governs the development and maintenance of neuropathic pain.

Prediction of fatal adverse prognosis in patients with fever-related diseases based on machine learning: A retrospective study.

BACKGROUND: Fever is the most common chief complaint of emergency patients. Early identification of patients at an increasing risk of death may avert adverse outcomes. The aim of this study was to establish an early prediction model of fatal adverse prognosis of fever patients by extracting key indicators using big data technology. METHODS: A retrospective study of patients' data was conducted using the Emergency Rescue Database of Chinese People's Liberation Army General Hospital. Patients were divided into the fatal adverse prognosis group and the good prognosis group. The commonly used clinical indicators were compared. Recursive feature elimination (RFE) method was used to determine the optimal number of the included variables. In the training model, logistic regression, random forest, adaboost and bagging were selected. We also collected the emergency room data from December 2018 to December 2019 with the same inclusion and exclusion criterion. The performance of the model was evaluated by accuracy, F1-score, precision, sensitivity and the areas under receiver operator characteristic curves (ROC-AUC). RESULTS: The accuracy of logistic regression, decision tree, adaboost and bagging was 0.951, 0.928, 0.924, and 0.924, F1-scores were 0.938, 0.933, 0.930, and 0.930, the precision was 0.943, 0.938, 0.937, and 0.937, ROC-AUC were 0.808, 0.738, 0.736, and 0.885, respectively. ROC-AUC of ten-fold cross-validation in logistic and bagging models were 0.80 and 0.87, respectively. The top six coefficients and odds ratio (OR) values of the variables in the Logistic regression were cardiac troponin T (CTnT) (coefficient=0.346, OR = 1.413), temperature (T) (coefficient=0.235, OR = 1.265), respiratory rate (RR) (coefficient= -0.206,OR = 0.814), serum kalium (K) (coefficient=0.137, OR = 1.146), pulse oxygen saturation (SPO2) (coefficient= -0.101, OR = 0.904), and albumin (ALB) (coefficient= -0.043, OR = 0.958). The weights of the top six variables in the bagging model were: CTnT, RR, lactate dehydrogenase, serum amylase, heartrate, and systolic blood pressure. CONCLUSIONS: The main clinical indicators of concern included CTnT, RR, SPO2, T, ALB and K. The bagging model and logistic regression model had better diagnostic performance comprehesively. Those may be conducive to the early identification of critical patients with fever by physicians.

Potent block of potassium channels by MEK inhibitor U0126 in primary cultures and brain slices.

U0126 (1,4-diamino-2,3-dicyano-1,4-bis (2-aminophenylthio) butadiene), a widely used mitogen-activated protein kinase kinase (MEK) inhibitor, was found to accelerate voltage-gated K+ channel (KV) inactivation in heterologous cells expressing several types of KV. The goal of this study was to examine whether U0126 at a concentration thought to specifically inhibit MEK signaling also inhibits KV in native neurons of primary cultures or brain slices. U0126 caused a dose-dependent inhibition of both the transient (IA) and sustained (IDR) components of K+ currents in hippocampal neurons. U0126 also exhibited much higher potency on the IA and IDR than the classical KV blockers 4-aminopyridine (4-AP) and tetraethylammonium (TEA). Consistent with its inhibitory effect on KV, U0126 broadened action potential duration, profoundly affected the repolarizing phase, and dramatically reduced firing frequency in response to current pulse injections. Despite the potent and reversible action of U0126 on Kv channels, PD98059, a structurally-unrelated MEK inhibitor, did not induce such an effect, suggesting U0126 may act independently of MEK inhibition. Together, these results raise cautions for using U0126 as a specific inhibitor for studying MEK signaling in neurons; on the other hand, further studies on the blocking mechanisms of U0126 as a potent inhibitor of KV may provide useful insights into the structure-function relationship of KV in general.

Beagle sciatic nerve regeneration across a 30 mm defect bridged by chitosan/PGA artificial nerve grafts.

Longitudinally oriented microstructures are essential for a nerve scaffold to promote the significant regeneration of injured peripheral axons across nerve gaps. In the current study, we present a novel nerve-guiding collagen-chitosan (CCH) scaffold that facilitated the repair of 30 mm-long sciatic nerve defects in beagles. The CCH scaffolds were observed with a scanning electron microscope. Eighteen beagles were equally divided into CCH group, autograft group and non-graft group. The posture and gait of each dog was recorded at 12 and 24 weeks after surgery. Electrophysiological tests, Fluoro-Gold retrograde tracing test, Histological assessment of gastrocnemius and immunofluorescent staining of nerve regeneration were performed. Our investigation of regenerated sciatic nerves indicated that a CCH scaffold strongly supported directed axon regeneration in a manner similar to that achieved by autologous nerve transplantation. In vivo animal experiments showed that the CCH scaffold achieved nerve regeneration and functional recovery equivalent to that achieved by an autograft but without requiring the exogenous delivery of regenerative agents or cell transplantation. We conclude that CCH nerve guides show great promise as a method for repairing peripheral nerve defects.

Development of adaptive pneumatic tourniquet systems based on minimal inflation pressure for upper limb surgeries.

BACKGROUND: Pneumatic tourniquets are medical devices that occlude blood flow to distal part of extremities and are commonly used in upper limb surgeries to provide a dry, clean and bloodless field. To decrease pressure-related injuries and potential risk of complications subjected to the high inflation pressure of pneumatic tourniquet, minimal inflation pressures are recommended. METHODS: A new occlusion pressure mathematical model for the upper limb was established based on the correlation analysis between several possible influencing parameters and the minimal pneumatic tourniquet pressure at which the peripheral pulse disappeared was recorded using a digital plethysmograph. A prototype of an adaptive pneumatic tourniquet which automatically varies the pressure in the tourniquet cuff according to the above prediction model was developed for the upper limb which used the lowest possible inflation pressure to achieve occlusion. The prototype comprises a blood pressure monitoring module, an inflatable tourniquet cuff, and a pressure relief mechanism to maintain an optimal cuff inflation pressure. Simulation experiments were conducted to verify the function and stability of the designed adaptive pneumatic tourniquet and clinical experiments using volunteers were undertaken to evaluate the performance of the prototype design in achieving adequate haemostasis in the upper limb. RESULTS: Results demonstrated that the mean arterial occlusion pressure was 152.3 ± 16.7 mmHg, obviously below the 250 to 300 mmHg previously recommended (J Bone Joint Surg Br 68:625-628, 1986 and Arthroscopy 11:307-311, 1995). CONCLUSIONS: In conclusion, this adaptive method and apparatus which can provide minimal inflation pressure may be a clinically practical alternative for upper limb surgery performed with pneumatic tourniquets.

[Interactive guided breathing technology].

OBJECT: Scientific guided breathing technology is to be studied based on the cardiopulmonary interaction. METHODS: Heart rate variability was used as the target function to study the smoothly respiratory relaxation procedure in order to acquire the common pattern of regular and slow breathing. RESULTS: Music based on the acquired common pattern was created and a musical pattern temporally-related to the breathing movement monitored by a sensor could be chosen to guide the breathing interactively.

[Design of a digital respiratory inductive plethysmography system].

A new type of respiratory inductive plethysmography (RIP) has keen designed based on digital demodulation technique with equal relative error. Compared with former amplitude demodulation, digital modulation RIP can obtain more accurate measurements of respiration and reduce the signal interference and distortion. But the system's power consumption is still a problem which needs to be solved in the future design.

[The polymorphism of Y chromosome and mtDNA distribution among two Bai populations].

In the same ethnic group, people residing at different places may have genetic difference. The difference can be the results of migration and admixture events happened in history. To clarify the genetic relationship and micro-evolution of two Bai ethnic populations residing in Yunnan and Hunan province respectively,we investigated their genetic difference from paternal and maternal genealogy with six other ethnic groups as outgroups. Fourteen loci from mtDNA and thirteen loci from Y chromosome were selected for genotyping using PCR-RFLP methods. Result showed that H6 and H8 are the same dominant Y chromosome haplotypes in two Bai groups. However,the distribution of mtDNA haplogroups showed difference between two Bai populations. D, B, M8 are the predominant haplogroups in Hunan Bai ethnic population, whereas M, G, F are dominant in Yunnan Bai ethnic population. Principal Component (PC) analysis based on the Y chromosome haplotypes showed that two Bai ethic populations cluster together. It shows a close paternal genetic relationship between two Bai ethnic populations. From the mtDNA PC plot, it is clear that Hunan Bai is close to Hunan Han and Tujia, whereas Yunnan Bai is close to ethnic groups living in Yunnan province. The difference of mtDNA haplogroup distribution in two Bai people may reflect the maternal gene flow between ethnic groups living in Hunan province after the ancestors of Hunan Bai migrated from Yunnan province to Hunan province 800 years ago.

[Principal component analysis of Y-chromosome haplotype distribution in 18 ethnic groups in Yunnan Province].

Based on the historical records, 18 of the 26 ethnic groups in Yunnan Province are the descendant populations of three ancient tribes, Bai-Yue, Bai-Pu and Di-Qiang, linguistically belonging to the Daic, Austro-Asiatic and Tibeto-Burman, respectively. In order to trace the origins of these native ethnic groups, a total of 13 East Asian specific Y-chromosome biallelic markers were used to study the genetic structure of 20 local populations covering all the 18 ethnic groups in Yunnan Province. Haplotypes were analysis by PCR-RFLP method. Our results showed that H11 and H12 were the predominant haplotypes in the descendant populations of Bai-Yue tribe. H5, H6 and H8 were the dominant haplotypes in Di-Qiang descendants, and the frequencies of H6, H8 and H11 were very high in the descendant populations of Bai-Pu. To investigate relationships among 20 populations, a three dimensional PC analysis were performed based on the distribution of the 13 haplotypes. All populations were divided into two clusters in the PC plot. The first cluster was mainly composed by the descendant populations of Bai-Yue, and the second one was mainly composed by the descendants of Di-Qiang tribe. This result indicated that Bai-Yue and Di-Qiang's paternal lineage had different origins, which was in agreement with the historical documents and linguistic classification.