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1.
Sci Data ; 11(1): 630, 2024 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-38876992

RESUMO

Rock abrasivity is one of the main factors affecting the wear of rock-cutting tools, which is usually quantified by the CERCHAR Abrasivity Index (CAI). Researchers and engineers study tool wear and predict tool life based on the CAI of rocks. However, there is still a lack of a dataset on rock properties, especially the abrasivity of various rocks. This paper reports the abrasive dataset of 10 kinds of rocks, including sedimentary rocks, metamorphic rocks, and igneous rocks, with the aid of the CERCHAR Abrasivity Test and digital measurement techniques. The dataset comprises rock abrasivity data, point cloud data for visualization, scratch photos, CERCHAR Abrasivity Test force data, and mechanical properties (uniaxial compressive strength) of rock samples. This dataset facilitates future research on rock abrasivity and rock-cutting tool wear.

2.
J Am Chem Soc ; 146(22): 15453-15463, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38795043

RESUMO

In contrast to the asymmetric synthesis of molecules with a single stereocenter or 1,2-adjacent stereocenters, the simultaneous construction of acyclic 1,3-nonadjacent stereocenters via a single catalyst in an enantioselective and diastereoselective manner remains a formidable challenge. Here, we demonstrate the enantioselective and diastereodivergent construction of 1,3-nonadjacent stereocenters through Ni-catalyzed reductive cyclization/cross-coupling of alkene-tethered aryl bromides and α-bromoamides, which represents the major remaining stereochemical challenge of cyclization/difunctionalization of alkenes. Using Ming-Phos as ligand, a diverse set of oxindoles containing 1,3-nonadjacent stereocenters were obtained with high levels of enantio- and diastereoselectivity. Mechanistic experiments and density functional theory calculations indicate that magnesium salt plays a key role in controlling the diastereoselectivity. Furthermore, another set of complementary stereoisomeric products were constructed from the same set of starting materials using Ph-Phox as ligand.

3.
Nat Commun ; 15(1): 2914, 2024 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-38575585

RESUMO

Carbo- and heterocycles are frequently used as crucial scaffolds in natural products, fine chemicals, and biologically and pharmaceutically active compounds. Transition-metal-catalyzed cyclization of 1,6-enynes has emerged as a powerful strategy for constructing functionalized carbo- and heterocycles. Despite significant progress, the regioselectivity of alkyne functionalization is entirely substrate-dependent. And only exo-cyclization/cross-coupling products can be obtained, while endo-selective cyclization/cross-coupling remains elusive and still poses a formidable challenge. In this study, we disclose a nickel-catalyzed switchable arylation/cyclization of 1,6-enynes in which the nature of the ligand dictates the regioselectivity of alkyne arylation, while the electrophilic trapping reagents determine the selectivity of the cyclization mode. Specifically, using a commercially available 1,10-phenanthroline as a ligand facilitates trans-arylation/cyclization to obtain seven-membered ring products, while a 2-naphthyl-substituted bisbox ligand promotes cis-arylation/cyclization to access six-membered ring products. Diastereoselective cyclizations have also been developed for the synthesis of enantioenriched piperidines and azepanes, which are core structural elements of pharmaceuticals and natural products possessing important biological activities. Furthermore, experimental and density functional theory studies reveal that the regioselectivity of the alkyne arylation process is entirely controlled by the steric hindrance of the ligand; the reaction mechanism involves exo-cyclization followed by Dowd-Beckwith-type ring expansion to form endo-cyclization products.

4.
Sci Rep ; 14(1): 7006, 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38523178

RESUMO

The low loading rate of the thin coal seam shearer drum is a severe obstacle to the efficient mining of thin seam resources, and the auxiliary drum loading through the cowl is an effective measure to alleviate this situation. However, the working mechanism of the coal cowl still remains unclear. In this paper, with the help of the discrete element method and the modeling experiment method, the effects of coal cowl's offset distance, tilt angle and wrap angle on the coal loading rate under different loading modes of the drum are investigated; and the significance of various factors and their interactions to the drum coal loading rate is explored by designing response surface experiments. The findings show that a monotonous negative correlation between the offset distance of the coal cowl and the coal loading rate is identified, and that a smaller offset distance can effectively improve the coal loading rate of the drum. The conveying torque is significantly increased, easily inducing the drum choking, coal recycling coal over-crushing. Along with the increasing tilt angle, the rate of ejection loading decreases monotonically, and the rate of pushing loading increases first and then decreases. Coal loading rate is weakly affected by changes in coal cowl's wrap angle. The results of response surface analysis reveal that the most significant factors affecting the drum's coal loading rate are tilt angle and offset distance in ejection and pushing loading modes, respectively. The conclusions drawn here offer implications for improving the coal loading performance of the thin coal seam shearer drum, as well as certain guidance on the optimal design of coal cowl parameters.

5.
Angew Chem Int Ed Engl ; 63(8): e202316035, 2024 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-38182545

RESUMO

Atropisomeric phosphines hold considerable significance in asymmetric catalysis, yet their synthesis presents a formidable challenge owing to intricate multistep procedures. In this context, a groundbreaking methodology has been presented for their preparation. This innovative approach entails an atroposelective rhodium-catalyzed C-H activation employing aryl and heteroaryl halides, chelated by a P(III) center. The essence of this strategy lies in its ability to directly construct chiral phosphine ligands in a single step, thereby exhibiting exceptional efficiency in terms of atom and redox economy. Illustrative examples serve to demonstrate the immense potential of in situ-formed ligands in asymmetric catalysis. Mechanistic experiments have further provided invaluable insights into this transformation.

6.
Arch Orthop Trauma Surg ; 144(2): 651-662, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38006437

RESUMO

INTRODUCTION: After locking plate (LP) fixation, secondary screw perforation (SSP) is the most common complication in proximal humerus fracture (PHF). SSP is the main cause of glenoid destruction and always leads to reoperation. This study aimed to identify independent risk parameters for SSP and establish an individualized risk prognostic model to facilitate its clinical management. METHODS: We retrospectively reviewed the medical information of patients with PHF who underwent open reduction and internal LP fixation at one medical center (n = 289) between June 2013 and June 2021. Uni- and multivariate regression analyses identified the independent risk factors. A novel nomogram was formulated based on the final independent risk factors for predicting the risk of SSP. We performed internal validation through concordance indices (C-index) and calibration curves. To implement the clinical use of the model, we performed decision curve analyses (DCA) and risk stratification according to the optimal cutoff value. RESULTS: A total of 232 patients who met the inclusion criteria were enrolled. The incidence of SSP was 21.98% at the last follow-up. We found that fracture type (odds ratio [OR], 3.111; 95% confidence interval [CI], 1.223-7.914; P = 0.017), postoperative neck-shaft angle (OR, 4.270; 95% CI 1.622-11.239; P = 0.003), the absence of calcar screws (OR, 3.962; 95% CI 1.753-8.955; P = 0.003), and non-medial metaphyseal support (OR,7.066; 95% CI 2.747-18.174; P = 0.000) were independent predictors of SSP. Based on these variables, we developed a nomogram that showed good discrimination (C-index = 0.815). The predicted values of the new model were in good agreement with the actual values demonstrated by the calibration curve. Furthermore, the model's DCA and risk stratification (cutoff = 140 points) showed significantly higher clinical benefits. CONCLUSIONS: We developed and validated a visual and personalized nomogram that could predict the individual risk of SSP and provide a decision basis for surgeons to create the most optional management plan. However, future prospective and externally validated design studies are warranted to verify our model's efficacy.


Assuntos
Fraturas do Úmero , Fraturas do Ombro , Humanos , Prognóstico , Estudos Retrospectivos , Parafusos Ósseos , Fixação Interna de Fraturas/efeitos adversos , Fraturas do Ombro/cirurgia , Placas Ósseas , Medição de Risco , Úmero/cirurgia , Resultado do Tratamento
7.
IEEE Trans Pattern Anal Mach Intell ; 45(4): 4009-4022, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34191722

RESUMO

Human performance capture is a highly important computer vision problem with many applications in movie production and virtual/augmented reality. Many previous performance capture approaches either required expensive multi-view setups or did not recover dense space-time coherent geometry with frame-to-frame correspondences. We propose a novel deep learning approach for monocular dense human performance capture. Our method is trained in a weakly supervised manner based on multi-view supervision completely removing the need for training data with 3D ground truth annotations. The network architecture is based on two separate networks that disentangle the task into a pose estimation and a non-rigid surface deformation step. Extensive qualitative and quantitative evaluations show that our approach outperforms the state of the art in terms of quality and robustness. This work is an extended version of [1] where we provide more detailed explanations, comparisons and results as well as applications.

8.
J Intensive Care Med ; 38(4): 349-357, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36066040

RESUMO

PURPOSE: Sepsis is a significant threat in the intensive care unit (ICU) worldwide because it has high morbidity and mortality rates. Early recognition and diagnosis of sepsis are essential for the prevention of adverse outcomes. The present study aimed to quantitatively assess the association between serum anion gap (AG) levels and 30- and 90-day all-cause mortality among sepsis patients. METHODS: Clinical data of patients diagnosed with sepsis were extracted from the Medical Information Mart for Intensive Care III (MIMIC III) database. Kaplan-Meier curves and Cox proportional hazards models were used to evaluate the association between serum AG levels and all-cause mortality. A receiver operating characteristic (ROC) curve was drawn to quantify the efficacy of using the serum AG level to predict all-cause mortality. RESULTS: A total of 3811 patients were included in the study. The Kaplan-Meier curves showed that patients with higher serum AG levels had a shorter survival time than those with lower levels. Serum AG levels were found to be highly effective in predicting all-cause mortality secondary to sepsis (30-day: AUROC = 0.703; 90-day: AUROC = 0.696). The Cox regression model further indicated that the serum AG level was an independent risk factor for 30- and 90-day mortality in sepsis (HR 3.44, 95% CI 2.97-3.99 for 30-day; HR 3.17, 95% CI 2.76-3.65 for 90-day, P < 0.001 for both). CONCLUSIONS: High serum AG may be considered as an alternative parameter for predicting the death risk in sepsis when other variables are not immediately available. Prospective large-scale studies are needed to support its predictive value in the clinic.


Assuntos
Equilíbrio Ácido-Base , Sepse , Humanos , Estudos Retrospectivos , Estudos Prospectivos , Prognóstico , Cuidados Críticos , Unidades de Terapia Intensiva , Curva ROC
9.
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi ; 36(10): 1312-1316, 2022 Oct 15.
Artigo em Chinês | MEDLINE | ID: mdl-36310471

RESUMO

Objective: To summarize the research progress of resorption of lumbar disc herniation (RLDH). Methods: The literature on RLDH at home and abroad in recent years was reviewed to summarize its influencing factors, pathogenesis, imaging findings, and predictive effect, as well as its influence on the treatment selection of lumbar disc herniation (LDH). Results: The main mechanism of RLDH is the combined effect of inflammatory response and neovascularization. Age, smoking, body mass index, and clinical manifestations are the influencing factors. Studies have shown that the annular enhancement around the nucleus pulposus on enhanced MRI images is the characteristic imaging manifestation of RLDH, which is a predictor of whether RLDH occurs. In the treatment of LDH, cyclooxygenase 2 inhibitors may have a negative impact on RLDH. Conclusion: The occurrence of RLDH suggests that strict conservative treatment is the first choice for LDH treatment, but surgery is still an important treatment method when the patient's symptoms and imaging symptoms don't significantly improved after conservative treatment.


Assuntos
Deslocamento do Disco Intervertebral , Humanos , Deslocamento do Disco Intervertebral/diagnóstico por imagem , Vértebras Lombares/cirurgia , Fatores de Risco , Recidiva
10.
Comb Chem High Throughput Screen ; 25(8): 1385-1397, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34525929

RESUMO

BACKGROUND: Wilms Tumor (WT) is the most common primary renal malignancy in children. Autophagy plays dual roles in the promotion and suppression of various cancers. OBJECTIVE: The goal of our study was to develop a novel autophagy-related gene (ARG) prognostic nomogram for WT. METHODS: The Cancer Genome Atlas (TCGA) database was used. We screened the expression profiles of ARGs in 136 WT patients. The differentially expressed prognostic ARGs were evaluated by multivariate Cox regression analysis and survival analysis. A novel prognostic nomogram based on the ARGs and clinical characteristics was established using multivariate Cox regression analysis. RESULTS: First, 69 differentially expressed ARGs were identified in WT patients. Then, multivariate Cox regression analysis was used to determine 4 key prognostic ARGs (CC3CL1, ERBB2, HIF-α and CXCR4) in WT. According to their ARG expression levels, the patients were clustered into high- and low-risk groups. Next, survival analysis indicated that high-risk patients had significantly poorer overall survival than low-risk patients. The results of functional enrichment analysis suggested that autophagy may play a tumor-suppressive role in the initiation of WT. Finally, a prognostic nomogram with a Harrell's concordance index (C-index) of 0.841 was used to predict the survival probability of WT patients by integrating clinical characteristics and the 4-ARG signature. The calibration curve indicated its excellent predictive performance. CONCLUSION: In summary, the ARG signature could be a promising biomarker for monitoring the outcomes of WT. We established a novel nomogram based on the ARG signature, which accurately predicts the overall survival of WT patients.


Assuntos
Nomogramas , Tumor de Wilms , Autofagia/genética , Criança , Humanos , Prognóstico , Análise de Sobrevida , Tumor de Wilms/diagnóstico , Tumor de Wilms/genética
11.
Bioengineered ; 12(1): 3503-3515, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34233591

RESUMO

Gestational diabetes mellitus (GDM) increases the risk of fetal heart malformations, though little is known about the mechanism of hyperglycemia-induced heart malformations. Thus, we aimed to reveal the global landscape of miRNAs and mRNAs in GDM-exposed fetoplacental arterial endothelial cells (dAECs) and establish regulatory networks for exploring the pathophysiological mechanism of fetal heart malformations in maternal hyperglycemia. Gene Expression Omnibus (GEO) datasets were used, and identification of differentially expressed miRNAs (DEMs) and genes (DEGs) in GDM was based on a previous sequencing analysis of dAECs. A miRNA-mRNA network containing 20 DEMs and 65 DEGs was established using DEMs altered in opposite directions to DEGs. In an in vivo study, we established a streptozotocin-induced pregestational diabetes mellitus (PGDM) mouse model and found the fetal cardiac wall thickness in different regions to be dramatically increased in the PGDM grouValidation of DEMs and DEGs in the fetal heart showed significantly upregulated expression of let-7e-5p, miR-139-5p and miR-195-5p and downregulated expression of SGOL1, RRM2, RGS5, CDK1 and CENPA. In summary, we reveal the miRNA-mRNA regulatory network related to fetal cardiac development disorders in offspring, which may shed light on the potential molecular mechanisms of fetal cardiac development disorders during maternal hyperglycemia.


Assuntos
Diabetes Gestacional/metabolismo , Células Endoteliais , MicroRNAs/genética , RNA Mensageiro/genética , Transcriptoma/genética , Animais , Células Cultivadas , Bases de Dados Genéticas , Diabetes Gestacional/genética , Células Endoteliais/citologia , Células Endoteliais/metabolismo , Feminino , Feto/irrigação sanguínea , Feto/citologia , Humanos , Camundongos , Camundongos Endogâmicos C57BL , MicroRNAs/metabolismo , Placenta/irrigação sanguínea , Placenta/citologia , Gravidez , RNA Mensageiro/metabolismo
12.
Pediatr Pulmonol ; 56(8): 2399-2412, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33983650

RESUMO

OBJECTIVES: To provide an updated review and meta-analysis on the efficacy and safety of sildenafil for treating persistent pulmonary hypertension in neonates (PPHN). METHODS: PubMed/Medline, SCOPUS, Cochrane Central Register of Controlled Trials, and Web of Science were searched from the inception of publication to January 2021. The principal outcomes include oxygenation parameters, hemodynamic metrics and echocardiographic measurements, as well as adverse outcomes. RESULTS: A total of eight studies were included with 216 term and premature neonates with PPHN. Compelling evidence showed the use of sildenafil could improve the prognosis of PPHN neonates, compared with baseline or placebo in neonates with PPHN, and a time-dependent pattern of the improvements can be observed. After 24 h of treatment, the Oxygenation index suggested a steady decrease (SD: -1.80, 95% confidence interval [CI]: -2.92, -0.67) and sildenafil exerted peak effects after 72 h of treatment (SD: -4.02, 95% CI: -5.45, -2.59). No clinically significant side effects were identified. Egger's test and funnel plots of the major outcomes were performed, and the publication bias was not significant. CONCLUSION: Improvements were shown in oxygenation index, pulmonary arterial pressure, and adverse outcomes after using sildenafil for PPHN in neonates. However, future research with robust longitudinal or randomized controlled design is still needed.


Assuntos
Hipertensão Pulmonar , Humanos , Hipertensão Pulmonar/tratamento farmacológico , Recém-Nascido , Citrato de Sildenafila/uso terapêutico
13.
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi ; 35(2): 149-153, 2021 Feb 15.
Artigo em Chinês | MEDLINE | ID: mdl-33624465

RESUMO

OBJECTIVE: To explore the effectiveness of open reduction and internal fixation for bipolar fracture-dislocation of the forearm. METHODS: Between June 2014 and March 2019, 14 patients with bipolar fracture-dislocation of the forearm were treated. There were 9 males and 5 females, aged from 19 to 52 years (mean, 34.9 years). There were 8 cases of falling injuries, 4 cases of traffic accident injuries, 1 case of sports injury, and 1 case of machine strangulation injury. The time from injury to admission was 2-48 hours, with an average of 16.6 hours. All patients were closed injuries. All patients were treated with open reduction and internal fixation; the upper radioulnar joints were treated with circumferential ligament repair or lateral collateral ligament repair according to the joint stability. And the patients with lower radioulnar joint instability were also treated with the TightRope plate with loop fixation. After 3 weeks of plaster fixation, the patients started functional exercises. The fracture healing time, stability and range of motion of wrist and elbow joints, and forearm rotation function were recorded. The effectiveness was evaluated by Anderson's forearm function score at last follow-up. RESULTS: The incisions healed by first intention. All 14 cases were followed up 12-36 months with an average of 24.8 months. All fractures healed, with an average healing time of 14.9 weeks (range, 12-18 weeks). The stabilities of the upper and lower radioulnar joints restored well. At last follow-up, the elbow flexion and extension range of motion was 65°-160°, with an average of 124.6°; the wrist flexion and extension range of motion was 115°-165°, with an average of 155.0°; the forearm rotation range of motion was 65°-165°, with an average of 154.6°. According to Anderson's forearm function score, 8 cases were excellent, 5 cases were good, and 1 case was unsatisfactory. CONCLUSION: The treatment of bipolar fracture-dislocation of the forearm needs comprehensive consideration and individualized treatment plan. The focus is to restore the anatomical structure of the radius and ulna and firm internal fixation, stabilize the upper and lower radioulnar joints, and perform functional exercises as soon as possible after operation to obtain satisfactory effectiveness.


Assuntos
Antebraço , Fixação Interna de Fraturas , Fraturas Ósseas , Adulto , Idoso , Feminino , Fraturas Ósseas/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Amplitude de Movimento Articular , Articulação do Punho/cirurgia , Adulto Jovem
14.
IEEE Trans Vis Comput Graph ; 27(10): 4009-4022, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-32746256

RESUMO

Synthesizing realistic videos of humans using neural networks has been a popular alternative to the conventional graphics-based rendering pipeline due to its high efficiency. Existing works typically formulate this as an image-to-image translation problem in 2D screen space, which leads to artifacts such as over-smoothing, missing body parts, and temporal instability of fine-scale detail, such as pose-dependent wrinkles in the clothing. In this article, we propose a novel human video synthesis method that approaches these limiting factors by explicitly disentangling the learning of time-coherent fine-scale details from the embedding of the human in 2D screen space. More specifically, our method relies on the combination of two convolutional neural networks (CNNs). Given the pose information, the first CNN predicts a dynamic texture map that contains time-coherent high-frequency details, and the second CNN conditions the generation of the final video on the temporally coherent output of the first CNN. We demonstrate several applications of our approach, such as human reenactment and novel view synthesis from monocular video, where we show significant improvement over the state of the art both qualitatively and quantitatively.


Assuntos
Gráficos por Computador , Processamento de Imagem Assistida por Computador/métodos , Redes Neurais de Computação , Gravação em Vídeo/métodos , Artefatos , Aprendizado Profundo , Humanos , Realidade Virtual
15.
IEEE Trans Vis Comput Graph ; 25(5): 2093-2101, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30794176

RESUMO

We propose the first real-time system for the egocentric estimation of 3D human body pose in a wide range of unconstrained everyday activities. This setting has a unique set of challenges, such as mobility of the hardware setup, and robustness to long capture sessions with fast recovery from tracking failures. We tackle these challenges based on a novel lightweight setup that converts a standard baseball cap to a device for high-quality pose estimation based on a single cap-mounted fisheye camera. From the captured egocentric live stream, our CNN based 3D pose estimation approach runs at 60 Hz on a consumer-level GPU. In addition to the lightweight hardware setup, our other main contributions are: 1) a large ground truth training corpus of top-down fisheye images and 2) a disentangled 3D pose estimation approach that takes the unique properties of the egocentric viewpoint into account. As shown by our evaluation, we achieve lower 3D joint error as well as better 2D overlay than the existing baselines.


Assuntos
Imageamento Tridimensional/métodos , Óculos Inteligentes , Bases de Dados Factuais , Aprendizado Profundo , Atividades Humanas , Humanos , Postura , Software , Gravação em Vídeo
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