COMPLETE KAHLER METRICS WITH POSITIVE HOLOMORPHIC SECTIONAL CURVATURES ON CERTAIN LINE BUNDLES(RELATED TO A COHOMOGENEITY ONE POINT OF VIEW ON A YAU CONJECTURE)

In this article,we study Kahler metrics on a certain line bundle over some compact Kahler manifolds to find complete Kahler metrics with positive holomorphic sectional(or bisectional)curvatures.Thus,we apply a strategy to a famous Yau conjecture with a co-homogeneity one geometry.

Optimized CUDA Implementation to Improve the Performance of Bundle Adjustment Algorithm on GPUs

The 3D reconstruction pipeline uses the Bundle Adjustment algorithm to refine the camera and point parameters. The Bundle Adjustment algorithm is a compute-intensive algorithm, and many researchers have improved its performance by implementing the algorithm on GPUs. In the previous research work, “Improving Accuracy and Computational Burden of Bundle Adjustment Algorithm using GPUs,” the authors demonstrated first the Bundle Adjustment algorithmic performance improvement by reducing the mean square error using an additional radial distorting parameter and explicitly computed analytical derivatives and reducing the computational burden of the Bundle Adjustment algorithm using GPUs. The naïve implementation of the CUDA code, a speedup of 10× for the largest dataset of 13,678 cameras, 4,455,747 points, and 28,975,571 projections was achieved. In this paper, we present the optimization of the Bundle Adjustment algorithm CUDA code on GPUs to achieve higher speedup. We propose a new data memory layout for the parameters in the Bundle Adjustment algorithm, resulting in contiguous memory access. We demonstrate that it improves the memory throughput on the GPUs, thereby improving the overall performance. We also demonstrate an increase in the computational throughput of the algorithm by optimizing the CUDA kernels to utilize the GPU resources effectively. A comparative performance study of explicitly computing an algorithm parameter versus using the Jacobians instead is presented. In the previous work, the Bundle Adjustment algorithm failed to converge for certain datasets due to several block matrices of the cameras in the augmented normal equation, resulting in rank-deficient matrices. In this work, we identify the cameras that cause rank-deficient matrices and preprocess the datasets to ensure the convergence of the BA algorithm. Our optimized CUDA implementation achieves convergence of the Bundle Adjustment algorithm in around 22 seconds for the largest dataset compared to 654 seconds for the sequential implementation, resulting in a speedup of 30×. Our optimized CUDA implementation presented in this paper has achieved a 3× speedup for the largest dataset compared to the previous naïve CUDA implementation.

MAXWELL-EINSTEIN METRICS ON COMPLETIONS OF CERTAIN C* BUNDLES

In this paper,we prove that for some completions of certain fiber bundles there is a Maxwell-Einstein metric conformally related to any given Kahler class.

His bundle pacing versus left bundle branch pacing on ventricular function in atrial fibrillation patients referred for pacing:a prospective crossover comparison

BACKGROUND His bundle pacing(HBP)and left bundle branch pacing(LBBP)both provide physiologic pacing which maintain left ventricular synchrony.They both improve heart failure(HF)symptoms in atrial fibrillation(AF)patients.We aimed to assess the intra-patient comparison of ventricular function and remodeling as well as leads parameters corresponding to two pacing modalities in AF patients referred for pacing in intermediate term.METHODS Uncontrolled tachycardia AF patients with both leads implantation successfully were randomized to either modality.Echocardiographic measurements,New York Heart Association(NYHA)classification,quality-of-life assessments and leads parameters were obtained at baseline and at each 6-month follow up.Left ventricular function including the left ventricular endosystolic volume(LVESV),left ventricular ejection fraction(LVEF)and right ventricular(RV)function quantified by tricuspid annular plane systolic excursion(TAPSE)were all assessed.RESULTS Consecutively twenty-eight patients implanted with both HBP and LBBP leads successfully were enrolled(69.1±8.1 years,53.6% male,LVEF 59.2%±13.7%).The LVESV was improved by both pacing modalities in all patients(n=23)and the LVEF was improved in patients with baseline LVEF at less than 50%(n=6).The TAPSE was improved by HBP but not LBBP(n=23).CONCLUSION In this crossover comparison between HBP and LBBP,LBBP was found to have an equivalent effect on LV function and remodeling but better and more stable parameters in AF patients with uncontrolled ventricular rates referred for atrioventricular node(AVN)ablation.HBP could be preferred in patients with reduced TAPSE at baseline rather than LBBP.

Characterization of retinal ganglion cell damage at single axon bundle level in mice by visible-light optical coherence tomography fibergraphy

Retinal ganglion cells(RGCs)receive synaptic inputs through their dendritic trees in the inner plexiform layer(IPL)and convey the visual information via their axons which form the optic nerve to the brain(Sanes and Masland,2015).In glaucoma,RGCs and their axons degenerate and die,leading to irreversible vision loss and eventually blindness if left untreated(Quigley,2016).

Left bundle branch pacing vs biventricular pacing in heart failure patients with left bundle branch block:A systematic review and meta-analysis

BACKGROUND Left bundle branch pacing(LBBP)is a novel pacing modality of cardiac resynchronization therapy(CRT)that achieves more physiologic native ventricular activation than biventricular pacing(BiVP).AIM To explore the validity of electromechanical resynchronization,clinical and echocardiographic response of LBBP-CRT.METHODS Systematic review and Meta-analysis were conducted in accordance with the standard guidelines as mentioned in detail in the methodology section.RESULTS In our analysis,the success rate of LBBP-CRT was determined to be 91.1%.LBBP CRT significantly shortened QRS duration,with significant improvement in echocardiographic parameters,including left ventricular ejection fraction,left ventricular end-diastolic diameter and left ventricular end-systolic diameter in comparison with BiVP-CRT.CONCLUSION A significant reduction in New York Heart Association class and B-type natriuretic peptide levels was also observed in the LBBP-CRT group vs BiVP-CRT group.Lastly,the LBBP-CRT cohort had a reduced pacing threshold at follow-up as compared to BiVP-CRT.

Effects of Hydrothermal Environment on the Deformation of the Thin Bamboo Bundle Veneer Laminated Composites

To overcome warping in thin bamboo bundle veneer laminated composites(TBLC),their hydrothermal deformation characteristics were systematically investigated in this study.It was found that TBLCs accelerated the release of internal stress in the thickness direction in a hydrothermal environment,which increased their warpage.TBLCs showed increased warpage in the width and diagonal directions upon increasing the temperature.The warpage of Type E increased by 155.88%and 66.67%in the width and diagonal directions,respectively,when the temperature increased from 25
C to 100
C.The symmetrical TBLC with cross-lay-up and odd layers displayed better hydrothermal stability.We revealed that the deformation of the TBLCs could be regulated under the synergistic effect of water and temperature.These results provide a scientific basis for improving the uniformity of bamboo bundle composite materials and for developing thin bamboo bundle fiber composite materials with designable structures and controllable performance.

Preventing surgical site infection using operating room bundle of care in patients undergoing elective exploratory laparotomy cholecystectomy surgery

Objective:Surgical procedures manifest immense risks to patients.One of the adverse events that healthcare professionals see as a threat to the patient’s health is the development of complications known as surgical site infection(SSI).Although several effor ts are being under taken to determine the proper means to reduce such complications,there is still a high incidence of SSI worldwide.Surgery requires knowledge in infection control and high precision in maintaining a clean surgical site.This study tested the effectiveness of an operating room(OR)bundle of care in preventing SSI in patients undergoing elective exploratory laparotomy cholecystectomy surgery.Methods:A quasi-experimental pretest and posttest design was utilized to determine its effectiveness.The study was composed of 60 par ticipants divided into two groups:30 subjects were selected to receive the OR bundle of care,while the other 30 subjects received the usual care.The groupings were determined through a systematic random sampling technique.The OR bundle of care had three interventions,namely:(1)maintaining perioperative normothermia,(2)no pre-operative surgical site hair removal,and(3)changing gloves before abdominal wall closure.These patients were evaluated using the standard instrument,Bates–Jensen Wound Assessment Tool(BWAT)in the post-intervention phases of the wound healing process,which are as follows:hemostasis,inflammatory,and proliferative phases.To describe the difference in the patients’wound status after implementation of the OR bundle of care in each post-intervention phase,Friedman’s test was used.To describe the difference in the patients’wound status in both groups after implementation of the OR bundle of care,the Mann–Whitney U test was used.Results:The patient’s wound status was lower,indicating a more healing process.Differences between the wound status of the control and the experimental group were observed on the third postoperative day.This indicates that the experimental group’s wound status healed much faster and more effectively than the control group based on the BWAT scoring severity scoring.A significant difference in the patient’s wound status from the hemostasis phase compared with the proliferative phase was observed.Conclusions:The OR bundle of care has been shown to be effective in preventing SSI in patients who had undergone exploratory laparotomy cholecystectomy surgery in the selected hospital,if there is uniform and consistent implementation of the said intervention.

A case of a successful post-transcatheter aortic valve replacement His bundle pacing

Dear editor,Transcatheter aortic valve replacement (TAVR) is a safe and effective treatment for severe aortic valve stenosis and aortic regurgitation. Multiple randomized trials have proved its therapeutic advantages in patients at any level of surgical risks.

Improving Accuracy and Computational Burden of Bundle Adjustment Algorithm Using GPUs

Bundle adjustment is a camera and point refinement technique in a 3D scene reconstruction pipeline. The camera parameters and the 3D points are refined by minimizing the difference between computed projection and observed projection of the image points formulated as a non-linear least-square problem. Levenberg-Marquardt method is used to solve the non-linear least-square problem. Solving the non-linear least-square problem is computationally expensive, proportional to the number of cameras, points, and projections. In this paper, we implement the Bundle Adjustment (BA) algorithm and analyze techniques to improve algorithmic performance by reducing the mean square error. We investigate using an additional radial distortion camera parameter in the BA algorithm and demonstrate better convergence of the mean square error. We also demonstrate the use of explicitly computed analytical derivatives. In addition, we implement the BA algorithm on GPUs using the CUDA parallel programming model to reduce the computational time burden of the BA algorithm. CUDA Streams, atomic operations, and cuBLAS library in the CUDA programming model are proposed, implemented, and demonstrated to improve the performance of the BA algorithm. Our implementation has demonstrated better convergence of the BA algorithm and achieved a speedup of up to 16× on the use of the BA algorithm on various datasets.

Left bundle branch pacing set to outshine biventricular pacing for cardiac resynchronization therapy?

The deleterious effects of long-term right ventricular pacing necessitated the search for alternative pacing sites which could prevent or alleviate pacinginduced cardiomyopathy.Until recently,biventricular pacing(BiVP)was the only modality which could mitigate or prevent pacing induced dysfunction.Further,BiVP could resynchronize the baseline electromechanical dssynchrony in heart failure and improve outcomes.However,the high non-response rate of around 20%-30%remains a major limitation.This non-response has been largely attributable to the direct non-physiological stimulation of the left ventricular myocardium bypassing the conduction system.To overcome this limitation,the concept of conduction system pacing(CSP)came up.Despite initial success of the first CSP via His bundle pacing(HBP),certain drawbacks including lead instability and dislodgements,steep learning curve and rapid battery depletion on many occasions prevented its widespread use for cardiac resynchronization therapy(CRT).Subsequently,CSP via left bundle branch-area pacing(LBBP)was developed in 2018,which over the last few years has shown efficacy comparable to BiVP-CRT in small observational studies.Further,its safety has also been well established and is largely free of the pitfalls of the HBP-CRT.In the recent metanalysis by Yasmin et al,comprising of 6 studies with 389 participants,LBBPCRT was superior to BiVP-CRT in terms of QRS duration,left ventricular ejection fraction,cardiac chamber dimensions,lead thresholds,and functional status amongst heart failure patients with left bundle branch block.However,there are important limitations of the study including the small overall numbers,inclusion of only a single small randomized controlled trial(RCT)and a small follow-up duration.Further,the entire study population analyzed was from China which makes generalizability a concern.Despite the concerns,the meta-analysis adds to the growing body of evidence demonstrating the efficacy of LBBP-CRT.At this stage,one must acknowledge that the fact that still our opinions on this technique are largely based on observational data and there is a dire need for larger RCTs to ascertain the position of LBBPCRT in management of heart failure patients with left bundle branch block.

Predictors of permanent pacemaker implantation following transcatheter aortic valve replacement-the search is still on!

Several anatomical,demographic,clinical,electrocardiographic,procedural,and valve-related variables can be used to predict the probability of developing con-duction abnormalities after transcatheter aortic valve replacement(TAVR)that necessitate permanent pacemaker(PPM)implantation.These variables include calcifications around the device landing zone and in the mitral annulus;pre-existing electrocardiographic abnormalities such as left and right bundle branch blocks(BBB),first-and second-degree atrioventricular blocks,as well as bifas-cicular and trifascicular blocks;male sex;diabetes mellitus(DM);hypertension;history of atrial fibrillation;renal failure;dementia;and use of self-expanding valves.The current study supports existing literature by demonstrating that type 2 DM and baseline right BBB are significant predictors of PPM implantation post-TAVR.Regardless of the side of the BBB,this study demonstrated,for the first time,a linear association between the incidence of PPM implantation post-TAVR and every 20 ms increase in baseline QRS duration(above 100 ms).After a 1-year follow-up,patients who received PPM post-TAVR had a higher rate of hospital-ization for heart failure and nonfatal myocardial infarction.

Comparison of His-purkinje bundle pacing and right ventricular inflow tract septal pacing in the elderly

Objective To compare the short-term clinical effect and electrical parameters of His-purkinje bundle pacing(HPBP) and right ventricular inflow tract septal pacing(RVIP) in the elderly. Methods Between April 2017 and September 2019, sixty patients with indications for permanent cardiac pacing and resynchronization therapy in Beijing Anzhen Hospital were divided into the HPBP and RVIP groups, and were analyzed. A ventricular pacing lead was implanted in left ventricular septal sites with left bundle potentials or His potentials in the HPBP group. The lead was placed in right ventricular inflow tract septal sites close to distal His-bundle regions without potentials from the His-purkinje conduction system in the RVIP group. Lead impedance, R wave amplitude, pacing thresholds, QRS duration, left ventricular ejection fraction(LVEF), and left ventricular end-diastolic diameter(LVEDD), mitral regurgitation area reflux, QTc, T wave directivity, Tp-e and Tp-e/QT ratio were compared between the HPBP and RVIP groups during the procedure and the short-month follow-up. Results No significant differences were found in lead impedance, R wave amplitude, QRS duration, LVEF, LVEDD, mitral regurgitation area reflux, QTc, T wave directivity, Tp-e and Tp-e/QT ratio between the HPBP and RVIP groups. However, the pacing threshold was significantly lower in the HPBP group than in the RVIP group(0.7 ± 0.2 vs. 0.9 ± 0.3 V, P = 0.02). Conclusions The efficacy and electrical parameters of HPBP is comparable with RVIP during the procedure and the short-term follow-up.

The Green Wall of Aksu

An afforestation project transforms a desert prefecture in Xinjiang into an oasis.YUSUPJAN Alim would win any reality show like Survivor hands down.The 36-year-old forest ranger started his career planting trees in the bleak and blazing Gobi Desert in 2004 in circumstances entirely different from today’s.At that time,there were no mobile phones,no GPS or transportation.The team would drive deep into the desert in a truck,carrying naans,the flatbread of Xinjiang that keeps for days.It was their staple,if not only,food.“We lived on Xinjiang naans and water for 15-20 days while working in the desert,”Yusupjan said.“We would dip the naan into water to make it soft.”When they worked,they tied their food in a bundle around their body so that if they got separated or even lost in the hostile desert,they would still have food.Every time they went in,Yusupjan would note the way carefully so that even if he got separated from his co-workers,he could still walk out of the desert alive.

Research Progress on the Application of Cluster Nursing Mode in ECMO-Assisted Patients

Cluster care,also known as cluster therapy,cluster intervention,or bundled therapy,is a series of evidence-based supportive joint care measures developed to improve the quality of care for specific patients or nursing issues.It is highly reliable and can effectively improve patient prognosis.This article summarized the application of cluster nursing care in extracorporeal membrane oxygenation(ECMO)-assisted patients and the problems faced to provide a reference for evidence-based decision-making in clinical practice.

Application effect for a care bundle in optimizing nursing of patients with severe craniocerebral injury

BACKGROUND Severe craniocerebral injury(STBI)is a critical physical trauma caused by a sudden external force acting on the head.The condition is complex and changeable,and disability and mortality rates are high.Although the life of STBI patients can be saved through treatment,the sequelae of consciousness,speech,cognitive impairment,stiffness,spasm,pain and abnormal behavior in the early rehabilitation stage can be a heavy burden to a family.In the past,routine nursing was often used to treat/manage STBI;however,problems,such as improper cooperation and untimely communication,reduced therapeutic effectiveness.AIM To investigate the effect of a proposed care bundle to optimize the first aid process and assess its effectiveness on the early rehabilitation nursing of patients with STBI.METHODS From January 2019 to December 2020,126 STBI patients were admitted to the emergency department of Chongqing Emergency Medical Center.These patients were retrospectively selected as the research participants in the current study.The study participants were then divided into a control group(61 cases)and a study group(65 cases).The control group was treated with routine nursing.The study group adopted the proposed care bundle.The National Institutes of Health Stroke Scale/Score and Glasgow Coma Scale(GCS)were used to evaluate neurological function before and after emergency treatment.After 3 mo of rehabilitation,experimental outcomes were assessed.These included the GCS,Barthel Index,complication rate,muscle strength grade and satisfaction.RESULTS There was no significant difference in gender,age,cause of injury and GCS between the two groups.After emergency,the National Institutes of Health Stroke Scale/Score of the study group(10.23±3.26)was lower than that of the control group(14.79±3.14).The GCS score of the study group(12.48±2.38)was higher than that of the control group(9.32±2.01).The arrival time of consultation in the study group was 20.56±19.12,and the retention time in the emergency room was 45.12±10.21,which were significantly shorter than those in the control group.After 3 mo of rehabilitation management,the GCS and Barthel Index of the study group were 14.56±3.75 and 58.14±12.14,respectively,which were significantly higher than those of the control group.The incidence of complications in the study group(15.38%)was significantly lower than that in the control group(32.79%).The proportion of muscle strength≥grade III in the study group(89.23%)was significantly higher than that in the control group(50.82%).The satisfaction of patients in the study group was significantly higher than that in the control group.CONCLUSION Care bundles are used to optimize the nursing process.During first-aid,care bundles can effectively improve the rescue effect and improve neurological function of STBI patients as well as shorten the treatment time.In early rehabilitation,they can effectively improve the consciousness of STBI patients,improve the activities of daily living,reduce the risk of complications,accelerate the recovery of muscle strength and improve their satisfaction.

Heat Transfer and Resistance Characteristics of Conical Spiral Tube Bundle Based on Field Synergy Principle

Conical spiral tube bundle are universally used in heat transfer enhancement in heat exchangers.The heat transfer and resistance of the tube bundle are affected greatly by the conical structure,so the analysis of it is necessary.In order to a further evaluation,the heat transfer and resistance characteristics of conical spiral tube bundle are investigated with regression analysis based on numerical simulation data.The correlations of heat transfer and pressure drop of conical spiral tube bundle are proposed both in laminar and turbulent fluid flow.On the based of the field synergy principle,the synergy of four vectors,the velocity,the velocity gradient,the temperature gradient and the pressure gradient,are calculated and discussed via the user defined function（UDF） program.The synergy angles β and θ,which respectively denote the performance of heat transfer enhancement and pressure drop of the conical spiral tube bundle,are analyzed.Finally,the comprehensive performance of the conical spiral tube is evaluated by the synergy angle γ and all of the three synergy angles of conical spiral tube bundle are compared to both bare tube and thin cylinder-interpolated tube.The analysis of the synergy angles shows that the heat transfer enhancement and pressure drop of conical spiral tube bundle are smaller than that of the thin cylinder-interpolated tube,while the comprehensive performance of conical spiral tube bundle is greater.The analysis of the heat transfer and pressure drop of conical spiral tube is valuable and instructional on the design and optimum of conical spiral tube bundle heat exchangers.

Buckling of filamentous actin bundles in filopodial protrusion

The mechanical behaviors of filamentous actin (F-actin) bundles play an essential role in filopodial protrusions at the leading edge of crawling cells. These bundles consist of parallel actin filaments that are hexagonally packed and interconnected via cross-linking proteins including α-actinin, filamin, and fascin. As pushing against the plasma membrane and/or external barriers, the actin bundles in filopodial protrusion inevitably encounter a compressive load. The bending stiffness and buckling stability of actin bundles are therefore important in determining the filopodia architecture and subsequent cell morphology. In this work, we employ a coarse-grained molecular dynamics model to investigate the buckling behaviors of cross-linked actin bundles under compression, which explicitly accounts for the properties of constituent filaments and the mechanical descriptions of cross-linkers. The bending stiffness of actin bundles exhibits a generic size effect depending on the number of filaments in the bundles, explicitly depending on the degree of inter-filament coupling. The distinct buckling modes are analyzed for bundles with different coupling states and strengths of cross-linkers. This study could clarify the stability and buckling mechanisms of parallelly packed actin bundles and the structure-function relations of mechanical components in filopodial protrusion.

High-precision regulation synthesis of Fe-doped Co_(2)P nanorod bundles as efficient electrocatalysts for hydrogen evolution in all-pH range and seawater

The hydrogen evolution reaction(HER)via water electrolysis has gained immense research attention.Seawater electrolysis provides great opportunities for sustainable energy production,but is extremely challenging.Transition metal phosphides are promising candidate electrocatalysts.Herein,we prepared a novel Fe-Co_(2)P bundle of nanorods(BNRs)for catalyzing the HER in seawater electrolysis and over the entire p H range.Cobalt phosphides with different crystal phases and morphologies were obtained by varying the Fe doping amount.The Co:Fe molar ratio of 1:0.5 was found to be optimum.The Fe doping improved the HER performance of Co_(2)P over the entire p H range by providing favorable electronic properties and morphology,lattice distortion,and special coordination environment.The Fe-Co_(2)P BNRs showed higher catalytic activity than 20%Pt/C in seawater at high potentials.The density functional theory calculations revealed that the Fe doping reduced the hydrogen binding strength of Co_(2)P to efficiently accelerate the HER kinetics and produce a favorable charge density.This study provides valuable insights into the design and development of high-efficiency HER catalysts for large-scale seawater electrolysis.

Exercise-induced left bundle branch block: an infrequent phenomenon: Report of two cases

Exercise-induced left bundle branch block(EI-LBBB)is infrequent phenomenon.We present two patients with angina pectoris who developed EI-LBBB during exercise tolerance test.The first patient with typical angina pectoris had significant obstructive coronary artery disease(CAD)requiring percutaneous coronary intervention of multiple lesions including placement of drug eluting stents.The second patient had atypical chest pain without signs of CAD at all.EI-LBBB occurred at a heart rate of 80 bpm and 141 bpm in the first and second patient,respectively.EI-LBBB remained visible through the test till the recovery period in the first patient at a heart rate of 83 bpm and disappeared at 96bpm in the second patient.Both patients with this infrequent phenomenon are discussed and the literature is reviewed.