Photocatalysis with atomically thin sheets.

Atomically thin sheets (e.g., graphene and monolayer molybdenum disulfide) are ideal optical and reaction platforms. They provide opportunities for deciphering some important and often elusive photocatalytic phenomena related to electronic band structures and photo-charges. In parallel, in such thin sheets, fine tuning of photocatalytic properties can be achieved. These include atomic-level regulation of electronic band structures and atomic-level steering of charge separation and transfer. Herein, we review the physics and chemistry of electronic band structures and photo-charges, as well as their state-of-the-art characterization techniques, before delving into their atomic-level deciphering and mastery on the platform of atomically thin sheets.

Hydrogen-Bonding Induced Crosslinked Polymer Network for Highly Stable Electrochromic Device and a Construction Strategy for Black-Bilayer Electrochromic Film.

This work presents a new strategy to achieve highly stable electrochromic devices and bilayer film construction. A novel solution-processable electrochromic polymer P1-Boc with quinacridone as the conjugated backbone and t-Boc as N-substituted non-conjugated solubilizing groups is designed. Thermal annealing of P1-Boc film results in the cleavage of t-Boc groups and the formation of N─H⋯O═C hydrogen-bonding crosslinked network, which changes its intrinsic solubility characteristics into a solvent-resistant P1 film. This film retains the electrochemical behavior and spectroelectrochemistry properties of the original P1-Boc film. Intriguingly, the electrochromic device based on the P1 film exhibits an ultrafast switching time (0.56/0.80 s at 523 nm) and robust electrochromic stability (retaining 88.4% of the initial optical contrast after 100 000 cycles). The observed cycle lifetime is one of the highest reported for all-organic electrochromic devices. In addition, a black-transparent bilayer electrochromic film P1/P2 is developed in which the use of the solvent-resistant P1 film as the bottom layer avoids interface erosion of the solution-processable polymer in a multilayer stacking.

Molecular Dynamics Investigation of Wettability Alteration of Quartz Surface under Thermal Recovery Processes.

One of the primary methods for bitumen and heavy oil recovery is a steam-assisted gravity drainage (SAGD) process. However, the mechanisms related to wettability alteration under the SAGD process still need to be fully understood. In this study, we used MD simulation to evaluate the wettability alteration under a steam injection process for bitumen and heavy oil recovery. Various oil droplets with different asphaltene contents were considered to determine the effect of an asphaltene content on the adsorption of the oil droplets onto quartz surfaces and wettability alteration. Based on the MD simulation outputs, the higher the asphaltene content, the higher the adsorption energy between the bitumen/heavy oil and quartz surfaces due to coulombic interactions. Additionally, the quartz surfaces became more oil-wet at temperatures well beyond the water boiling temperature; however, they were extremely water-wet at ambient conditions. The results of this work provide in-depth information regarding wettability alteration during in situ thermal processes for bitumen and heavy oil recovery. Furthermore, they provide helpful information for optimizing the in situ thermal processes for successful operations.

Is Biportal Endoscopic Spine Surgery More Advantageous Than Uniportal for the Treatment of Lumbar Degenerative Disease? A Meta-Analysis.

Background and Objectives: To estimate the clinical outcomes of uniportal and biportal full-endoscopic spine surgery for the treatment of lumbar degenerative disease (LDD), and to provide the latest evidence for clinical selection. Materials and Methods: Relevant literatures published in PubMed, Web of Science, Embase, CNKI, and WanFang Database before 21 November 2021 were searched systematically. Two researchers independently screened the studies, extracted data, and evaluated the risk of bias of the included studies. The systematic review and meta-analysis were performed using the Review Manager software (version 5.4; The Cochrane Collaboration). Results: A total of seven studies were included in this meta-analysis, including 198 patients in a uniportal endoscopy group and 185 patients in a biportal endoscopy group. The results of this meta-analysis demonstrated that the biportal endoscopy group experienced less intraoperative estimated blood loss (WMD = -2.54, 95%CI [-4.48, -0.60], p = 0.01), while the uniportal endoscopy group displayed significantly better recovery results in Visual Analog Scale (VAS) assessments of the back within 3 days of surgery (WMD = 0.69, 95%CI [0.02, 1.37], p = 0.04). However, no significant differences in operation time, length of hospital stay, complication rates, Oswestry Disability Index (ODI) (within 3 months), ODI (last follow-up), VAS for back (within 3 months), VAS for back (last follow-up), and VAS for leg (within 3 days, within 3 months, last follow-up) were identified between the two groups. Conclusions: According to our meta-analysis, patients who underwent the uniportal endoscopic procedure had more significant early postoperative back pain relief than those who underwent the biportal endoscopic procedure. Nevertheless, both surgical techniques are safe and effective.

Structural insights revealed by crystal structures of CYP76AH1 and CYP76AH1 in complex with its natural substrate.

CYP76AH1 is the key enzyme in the biosynthesis pathway of tanshinones in Salvia miltiorrhiza, which are famous natural products with activities against various heart diseases and others. CYP76AH1 is a membrane-associated typical plant class II cytochrome P450 enzyme and its catalytic mechanism has not to be clearly elucidated. Structural determination of eukaryotic P450 enzymes is extremely challenging. Recently, we solved the crystal structures of CYP76AH1 and CYP76AH1 in complex with its natural substrate miltiradiene. The structure of CYP76AH1 complexed with miltiradiene is the first plant cytochrome P450 structure in complex with natural substrate. The studies revealed a unique array pattern of amino acid residues, which may play an important role in orienting and stabilizing the substrate for catalysis. This work would provide structural insights into CYP76AH1 and related P450s and the basis to efficiently improve tanshinone production by synthetic biology techniques.

n-decane diffusion in carbon nanotubes with vibration.

Carbon nanotubes (CNTs) have a wide range of applications in nanotechnology engineering. This research aims to quantify the effect of wall vibration on n-decane molecules' diffusion in double-walled CNTs (DWNTs) with different diameters and determine the diffusion mechanisms behind it. Molecular dynamics simulations are performed to generate mass density profiles of confined n-decane molecules. The root mean square fluctuation and mean squared displacement analyses show that the confinement suppresses n-decane molecules' fluctuations. A self-diffusion coefficient of n-decane molecules in a 13.6 Å-diameter DWNT is the largest. However, the vibration enhancement of the n-decane molecules' diffusion in a 27.1 Å-diameter DWNT is 207%, more extensive than that in 13.6 Å-diameter and 10.8 Å-diameter DWNTs. The n-decane-CNT attractive interactions, extreme confinement, and surface friction affect the n-decane molecules' diffusion in CNTs with vibration.

Surface charging parameters of charged particles in symmetrical electrolyte solutions.

Surface electric charge of dispersed particles is an essential determinant of physicochemical properties, coagulation and flocculation processes, and stability of colloidal solutions. Size-dependence of surface potential, charge density, and total surface charge of suspended charged particles has recently received attention in the literature. Despite the clear significance of understanding such dependence, very few studies have been devoted to this problem, with contradictory results of the relationship type. Currently, there is no analytical formula to represent explicit relationships between surface charging parameters and particle size. This research work is directed at development of accurate physics-based formulas for quantification of curvature-dependence of surface potential, surface charge density, and total surface charge for cylindrical and spherical charged particles immersed in a symmetrical electrolyte solution. First, a non-dimensional approach is adopted to simplify the problems, overcoming the difficulty of dealing with multiple influential variables. Then, to reduce the degrees of freedom of the problems under consideration, Gauss's law is combined with the condition of electro-neutrality in an electrical double layer (EDL). Next, the resulting complex integral equations are solved to construct characteristic curves and to express the dimensionless surface charging parameters explicitly as a function of the dimensionless particle radius. The new theoretical expressions are founded on approximate analytical and numerical solutions of the nonlinear Poisson-Boltzmann (PB) equation in cylindrical and spherical geometries. Afterwards, the solutions of the non-dimensionalized problems are dimensionalized to derive accurate explicit closed-form expressions, describing how surface charging parameters are related to the radius of a charged particle, properties of the solution, and thermodynamic conditions. These analytical formulas enable researchers to properly determine surface potential, surface charge density, total surface charge, and radius of dispersed particles by characterizing only one of them. Finally, the validity of the commonly-held hypothesis that surface charge density is independent of particle size is examined at the end of this study.

Wettability effect on nanoconfined water flow.

Understanding and controlling the flow of water confined in nanopores has tremendous implications in theoretical studies and industrial applications. Here, we propose a simple model for the confined water flow based on the concept of effective slip, which is a linear sum of true slip, depending on a contact angle, and apparent slip, caused by a spatial variation of the confined water viscosity as a function of wettability as well as the nanopore dimension. Results from this model show that the flow capacity of confined water is 10-1∼107 times that calculated by the no-slip Hagen-Poiseuille equation for nanopores with various contact angles and dimensions, in agreement with the majority of 53 different study cases from the literature. This work further sheds light on a controversy over an increase or decrease in flow capacity from molecular dynamics simulations and experiments.

Ultrahigh Water Flow Enhancement by Optimizing Nanopore Chemistry and Geometry.

The high permeability of nanoporous membranes is crucial for separation processes and energy conversions, especially for the world today that is facing growing water scarcity and energy demands. Unfortunately, further improving permeability, without sacrificing the required selectivity for specific applications, is still extremely challenging. Here, we shed light on the mechanisms of extremely high water permeability of artificial nanopores with the aquaporin-inspired pore geometry and propose a simple yet practical optimization strategy by using computational research to relate nanopore chemistry and geometry to permeability performance. We demonstrated that an ultrahigh water flow enhancement, up to 7 orders of magnitude, can be achieved by optimizing the combination of chemical and geometrical parameters of bioinspired artificial nanopores. Moreover, we addressed an existing debate over the water flow enhancement spanning over 10-1 to 105, attributed to the huge differences in chemical and geometrical properties. Our work provides a guideline to the design and optimization of nanofluidic devices with excellent performance.

Conjugation-broken thiophene-based electropolymerized polymers with well-defined structures: effect of conjugation lengths on electrochromic properties.

A series of monomers containing tetraphenylsilane connected to different thiophenes such as thiophene, bithiophene and terthiophene were designed and synthesized and were further used to prepare the corresponding polymers via electrochemical polymerization (pSiTPTP, pSiTPBTP and pSiTPTTP). From the polymers, the effective conjugate elements were well defined as bithiophene, quaterthiophene and sexithiophene because the sp3 Si atom can block the conjugation between the thiophene units in the polymer backbone. The spectroelectrochemical results indicated that pSiTPTP is incapable of electrochromism, which may be attributed to the insufficient conjugation length of the independent bithiophene. In contrast, both pSiTPBTP and pSiTPTTP exhibited obvious electrochromic properties and furthermore, pSiTPTTP displayed a shorter switching time and better stability. Such different electrochemical behaviors can be ascribed to the looser stacking structure and lower oxidation potential of pSiTPTTP with the independent sexithiophene unit. The EIS measurements also confirmed the lower charge-transfer resistance and higher ion-diffusion rate of pSiTPTTP with the independent sexithiophene unit. Hence, we can conclude that the effects of the electrochromic behavior of the conjugation-broken polythiophene derivatives depend on the increased conjugation length of the thiophene repeating unit, in which the inadequate electrochromism with bithiophene units can change to superior electrochromic properties with increased sexithiophene units.

Manipulating the Flow of Nanoconfined Water by Temperature Stimulation.

The manipulation of a nanoconfined fluid flow is a great challenge and is critical in both fundamental research and practical applications. Compared with chemical or biochemical stimulation, the use of temperature as controllable, physical stimulation possesses huge advantages, such as low cost, easy operation, reversibility, and no contamination. We demonstrate an elegant, simple strategy by which temperature stimulation can readily manipulate the nanoconfined water flow by tuning interfacial and viscous resistances. We show that with an increase in temperature, the water fluidity is decreased in hydrophilic nanopores, whereas it is enhanced by at least four orders of magnitude in hydrophobic nanopores, especially in carbon nanotubes with a controlled size and atomically smooth walls. We attribute these opposing trends to a dramatic difference in varying surface wettability that results from a small temperature variation.

ProLanGO: Protein Function Prediction Using Neural Machine Translation Based on a Recurrent Neural Network.

With the development of next generation sequencing techniques, it is fast and cheap to determine protein sequences but relatively slow and expensive to extract useful information from protein sequences because of limitations of traditional biological experimental techniques. Protein function prediction has been a long standing challenge to fill the gap between the huge amount of protein sequences and the known function. In this paper, we propose a novel method to convert the protein function problem into a language translation problem by the new proposed protein sequence language "ProLan" to the protein function language "GOLan", and build a neural machine translation model based on recurrent neural networks to translate "ProLan" language to "GOLan" language. We blindly tested our method by attending the latest third Critical Assessment of Function Annotation (CAFA 3) in 2016, and also evaluate the performance of our methods on selected proteins whose function was released after CAFA competition. The good performance on the training and testing datasets demonstrates that our new proposed method is a promising direction for protein function prediction. In summary, we first time propose a method which converts the protein function prediction problem to a language translation problem and applies a neural machine translation model for protein function prediction.

Variable is better than invariable: sparse VSS-NLMS algorithms with application to adaptive MIMO channel estimation.

Channel estimation problem is one of the key technical issues in sparse frequency-selective fading multiple-input multiple-output (MIMO) communication systems using orthogonal frequency division multiplexing (OFDM) scheme. To estimate sparse MIMO channels, sparse invariable step-size normalized least mean square (ISS-NLMS) algorithms were applied to adaptive sparse channel estimation (ACSE). It is well known that step-size is a critical parameter which controls three aspects: algorithm stability, estimation performance, and computational cost. However, traditional methods are vulnerable to cause estimation performance loss because ISS cannot balance the three aspects simultaneously. In this paper, we propose two stable sparse variable step-size NLMS (VSS-NLMS) algorithms to improve the accuracy of MIMO channel estimators. First, ASCE is formulated in MIMO-OFDM systems. Second, different sparse penalties are introduced to VSS-NLMS algorithm for ASCE. In addition, difference between sparse ISS-NLMS algorithms and sparse VSS-NLMS ones is explained and their lower bounds are also derived. At last, to verify the effectiveness of the proposed algorithms for ASCE, several selected simulation results are shown to prove that the proposed sparse VSS-NLMS algorithms can achieve better estimation performance than the conventional methods via mean square error (MSE) and bit error rate (BER) metrics.

Critical Condition of the Depth Limit of Oil Accumulation of Carbonate Reservoirs and Its Exploration Significance in the Lower Ordovician of the Tazhong Area in the Tarim Basin.

Carbonate rocks typically constitute porous media, making the study of hydrocarbon accumulation in carbonate reservoirs an essential area of research. In the Tazhong area of the Tarim Basin, specifically within the Lower Ordovician stratum exceeding 7000 m, effective reservoirs and industrial liquid hydrocarbon accumulations persist. However, the existence of a depth limit of oil accumulation (DLOA) for oil accumulation in carbonate reservoirs remains unclear, posing a challenge for explorers. This study quantitatively characterizes the critical condition of DLOA in deep carbonate reservoirs from the perspective of hydrocarbon accumulation dynamics. Through comprehensive experimental analysis, statistical assessments, and numerical simulations, it also forecasts the potential for deep oil exploration. Based on the results of mercury injection experiments on 350 carbonate rock cores collected from 19 drilling wells in the deep Lower Ordovician, it was found that the reservoir is compact and exhibits significant heterogeneity. The driving force for oil accumulation is the capillary pressure difference between the surrounding rock and the reservoir. A greater capillary pressure difference indicates improved oil-bearing properties within the reservoir. When the capillary pressure difference between the reservoir and surrounding rock reaches zero, oil accumulation cannot occur, marking the critical condition of DLOA. The critical pore throat radius for DLOA in the deep Lower Ordovician carbonate rocks in the Tazhong area of the Tarim Basin is determined to be 0.01 µm, and the DLOA is estimated at 9000 m. This study confirms that the maximum depth for the embedded Lower Ordovician carbonate reservoir in the Tazhong area does not surpass this limit. Consequently, oil exploration in deep carbonate rocks within this stratum is both feasible and promising. The findings from this study hold significant importance in scientifically predicting favorable areas for oil exploitation in deep layers and offer valuable insights into understanding the oil flow in carbonate rocks.

Highly Dispersed Ni Atoms and O3 Promote Room-Temperature Catalytic Oxidation.

Transition metal oxides are promising catalysts for catalytic oxidation reactions but are hampered by low room-temperature activities. Such low activities are normally caused by sparse reactive sites and insufficient capacity for molecular oxygen (O2) activation. Here, we present a dual-stimulation strategy to tackle these two issues. Specifically, we import highly dispersed nickel (Ni) atoms onto MnO2 to enrich its oxygen vacancies (reactive sites). Then, we use molecular ozone (O3) with a lower activation energy as an oxidant instead of molecular O2. With such dual stimulations, the constructed O3-Ni/MnO2 catalytic system shows boosted room-temperature activity for toluene oxidation with a toluene conversion of up to 98%, compared with the O3-MnO2 (Ni-free) system with only 50% conversion and the inactive O2-Ni/MnO2 (O3-free) system. This leap realizes efficient room-temperature catalytic oxidation of transition metal oxides, which is constantly pursued but has always been difficult to truly achieve.

Knockdown of Pokemon protein expression inhibits hepatocellular carcinoma cell proliferation by suppression of AKT activity.

Overexpression of Pokemon, which is an erythroid myeloid ontogenic factor protein, occurs in different cancers, including hepatocellular carcinoma (HCC). Pokemon is also reported to have an oncogenic activity in various human cancers. This study investigated the effect of Pokemon knockdown on the regulation of HCC growth. POK shRNA suppressed the expression of Pokemon protein in HepG2 cells compared to the negative control vector-transfected HCC cells. Pokemon knockdown also reduced HCC cell viability and enhanced cisplatin-induced apoptosis in HCC cells. AKT activation and the expression of various cell cycle-related genes were inhibited following Pokemon knockdown. These data demonstrate that Pokemon may play a role in HCC progression, suggesting that inhibition of Pokemon expression using Pokemon shRNA should be further evaluated as a novel target for the control of HCC.

Potential alternative drug treatment for bone giant cell tumor.

Background: Bone giant cell tumor (BGCT) is one of the world's major disease types of locally aggressive bone tumors. In recent years, denosumab treatment has been introduced before curettage surgery. However, the current therapeutic was practical only sometimes, given the local recurrence effects after discontinuation of denosumab. Due to the complex nature of BGCT, this study aims to use bioinformatics to identify potential genes and drugs associated with BGCT. Methods: The genes that integrate BGCT and fracture healing were determined by text mining. The gene was obtained from the pubmed2ensembl website. We filtered out common genes for the function, and signal pathway enrichment analyses were implemented. The protein-protein interaction (PPI) networks and the hub genes were screened by MCODE built-in Cytoscape software. Lastly, the confirmed genes were queried in the Drug Gene Interaction Database to determine potential genes and drugs. Results: Our study finally identified 123 common specific genes in bone giant cell tumors and fracture healing text mining concepts. The GO enrichment analysis finally analyzed 115 characteristic genes in BP, CC, and MF. We selected 10 KEGG pathways and identified 68 characteristic genes. We performed protein-protein interaction analysis (PPI) on 68 selected genes and finally identified seven central genes. In this study, these seven genes were substituted into drug-gene interactions, and there were 15 antineoplastic drugs, 1 anti-involving drug, and 1 anti-influenza drug. Conclusion: The 7 genes (including ANGPT2, COL1A1, COL1A2, CTSK, FGFR1, NTRK2, and PDGFB) and 17 drugs, which have not been used in BGCT, but 6 of them approved by the FDA for other diseases, could be potential genes and drugs, respectively, to improve BGCT treatment. In addition, the correlation study and analysis of potential drugs through genes provide great opportunities to promote the repositioning of drugs and the study of pharmacology in the pharmaceutical industry.

Comparison of clinical outcomes with proximal femoral nail anti-rotation versus dynamic hip screw for unstable intertrochanteric femoral fractures: A meta-analysis.

BACKGROUND: The aim of this meta-analysis was to evaluate the advantages and disadvantages of proximal femoral nail anti-rotation (PFNA) versus dynamic hip screw (DHS) for the treatment of unstable intertrochanteric fractures, including the available evidence drawn from the literature. METHODS: A systematic search was conducted to identify available and relevant randomized controlled trials and retrospective comparative observational studies regarding PFNA compared against DHS in treating unstable femoral intertrochanteric fractures in Embase, PubMed, Cochrane Library, Web of Science, and Scopus Online up to February 12, 2022. Data from the included studies were extracted independently by 2 reviewers and analyzed using RevMan 5.3, and the quality of the studies was assessed. RESULTS: Five randomized controlled trials and 12 observational studies were recruited and met the inclusion criteria, which consisted of 1332 patients with PFNA and 1271 patients with DHS. The results of the meta-analysis showed that, compared with the DHS, PFNA exhibited a beneficial role in postoperative Harris Hip Scores, operation time, intraoperative blood loss, length of hospital stay, fracture healing time and full weight-bearing time, limb shortening, cutout, reoperation, union problems, the varus collapse of the femoral head/neck, and infection; however, DHS was superior to PFNA in hidden blood loss (relative risk [RR] = 139.81, 95% confidence interval [CI] [136.18, 143.43], P < .00001), postoperation drainage (RR = -17.85, 95% CI [-30.10, -5.60], P = .004), total blood loss (RR = 50.34, 95% CI [42.99, 57.69], P < .00001), and femoral shaft fracture (RR = 4.72, 95% CI [1.15, 19.32], P = .03) treated by DHS were significantly decreased, compared with those by PFNA; however, no significant differences were observed in tip-apex distance, fixation failures, screw migration, or other complicants between the 2 surgical methods. CONCLUSION: Analysis of a large number of relevant clinical indicators available shows that PFNA has better clinical manifestation than DHS in treating unstable femoral intertrochanteric fractures.

Photoreforming for Lignin Upgrading: A Critical Review.

Photoreforming of lignocellulosic biomass to simultaneously produce gas fuels and value-added chemicals has gradually emerged as a promising strategy to alleviate the fossil fuels crisis. Compared to cellulose and hemicellulose, the exploitation and utilization of lignin via photoreforming are still at the early and more exciting stages. This Review systematically summarizes the latest progress on the photoreforming of lignin-derived model components and "real" lignin, aiming to provide insights for lignin photocatalytic valorization from fundamental to industrial applications. Considering the complexity of lignin physicochemical properties, related analytic methods are also introduced to characterize lignin photocatalytic conversion and product distribution. We finally put forward the challenges and perspective of lignin photoreforming, hoping to provide some guidance to valorize biomass into value-added chemicals and fuels via a mild photoreforming process in the future.

Recent advances and progress in biotemplate catalysts for electrochemical energy storage and conversion.

Complex structures and morphologies in nature endow materials with unexpected properties and extraordinary functions. Biotemplating is an emerging strategy for replicating nature structures to obtain materials with unique morphologies and improved properties. Recently, efforts have been made to use bio-inspired species as a template for producing morphology-controllable catalysts. Fundamental information, along with recent advances in biotemplate metal-based catalysts are presented in this review through discussions of various structures and biotemplates employed for catalyst preparation. This review also outlines the recent progress on preparation routes of biotemplate catalysts and discusses how the properties and structures of these templates play a crucial role in the final performance of metal-based catalysts. Additionally, the application of bio-based metal and metal oxide catalysts is highlighted for various key energy and environmental technologies, including photocatalysis, fuel cells, and lithium batteries. Biotemplate metal-based catalysts display high efficiency in several energy and environmental systems. Note that this review provides guidance for further research in this direction.