Real-time localization for underwater equipment using an extremely low frequency electric field

A new real-time underwater equipment location method adopting an electric field induced by a standard current source is proposed.Our goals were real-time tracking and location of stationary or moving underwater equipment both in shallow and deep seas,under noisy conditions.The main features of this method are as follows:(1)a standard current source on the water surface,which can be towed by a vehicle,consisting of two electrodes,a signal generator,and a GPS unit;(2)measurement of the extremely low frequency(ELF)electric field emitted by the current source,made possible by electric field sensors on the underwater equipment;(3)position of the underwater equipment is estimated in real time based on a progressive update extended Kalman filter(PUEKF),which is carried out using the propagation model of an ELF electric field because the electric field at the position of the underwater equipment and the current source position are known.We verified the accuracy of our method and confirmed real-time location feasibility through numerical,physical scale,and real-time sea experiments.Through numerical experiments,we verified that our method works for underwater equipment location in real-world conditions,and the location error can be less than 0.2 m.Next,real-time location experiments for stationary underwater measuring equipment in water tank were conducted.The result shows that the location error can be less than 0.1 m.We also confirmed real-time location feasibility through the use of offshore experiment.We expect that our method will complement conventional underwater acoustic location methods for underwater equipment in acoustically noisy environments.

Photobiomodulation provides neuroprotection through regulating mitochondrial fission imbalance in the subacute phase of spinal cord injury

Increasing evidence indicates that mitochonarial lission imbalance plays an important role in derayed neuronal cell death. Our previous study round that photo biomodulation improved the motor function of rats with spinal cord injury.However,the precise mechanism remains unclear.To investigate the effect of photo biomodulation on mitochondrial fission imbalance after spinal cord injury,in this study,we treated rat models of spinal co rd injury with 60-minute photo biomodulation(810 nm,150 mW) every day for 14 consecutive days.Transmission electron microscopy results confirmed the swollen and fragmented alte rations of mitochondrial morphology in neurons in acute(1 day) and subacute(7 and 14 days) phases.Photo biomodulation alleviated mitochondrial fission imbalance in spinal cord tissue in the subacute phase,reduced neuronal cell death,and improved rat posterior limb motor function in a time-dependent manner.These findings suggest that photobiomodulation targets neuronal mitochondria,alleviates mitochondrial fission imbalance-induced neuronal apoptosis,and thereby promotes the motor function recovery of rats with spinal cord injury.

Giant simple hepatic cyst with multiple elevated serum tumormarkers: A case report

BACKGROUND Simple hepatic cysts are relatively common in adults, and mostly appear asasymptomatic incidental radiologic findings. Occasionally, a large cyst will causesymptoms. Elevations in the serum biomarkers protein induced by vitamin Kabsence (PIVKA)-II, cancer antigen (CA) 12-5, and CA19-9 are often associatedwith malignant tumors in the liver or bile ducts. This is the first report to describea case of hepatic cyst with elevated levels of PIVKA-II and CA12-5.CASE SUMMARY An 84-year-old Chinese woman was admitted with gradual abdominal distension.Her symptoms started 1 year ago, and she had poor appetite and a weight loss of5 kg within the past 2 wk. She denied any symptoms associated with abdominalpain, fever and chills, nausea and vomiting, etc. The abdomen was enlarged, morein the right upper quadrant, without tenderness. Laboratory examination showedsignificantly increased serum levels of PIVKA-II, CA12-5, and CA19-9. Acomputed tomography scan revealed multiple round cysts in the liver with clearboundaries. The largest cyst was 20.1 cm × 12.2 cm × 19.6 cm in size, located in theright lobe of the liver with mild dilatation of the intrahepatic bile duct, but therewas no contrast enhancement. Percutaneous drainage on the largest hepatic cystand polycinnamol sclerosing agent injection into the cyst cavity were performed.After treatment, the patient’s symptoms relieved and the elevated serum tumormakers reduced to the normal levels dramatically.CONCLUSION The present report identifies an unusual case of a giant hepatic cyst with markedelevation of serum tumor marker levels of PIVKA-II, CA12-5, and CA19-9. Aftertreatment, these three serum markers dramatically decreased to normal levels.The mechanisms for the elevation of these tumor markers may be as follows: (1) Agiant hepatic cyst compresses the liver, causing injury to the hepatocytes, whichmay lead to secretion of a large amount of PIVKA-II;and (2) Some tumorassociatedantigens, such as carcinoembryonic antigen, CA19-9, CA12-5, andCA15-3, are expressed on inflammatory cells.

Unexpected difficult airway due to severe upper tracheal distortion:A case report

BACKGROUND Difficult airway is a significant cause of anesthesia-associated death and disability.Currently,physical examinations of thyromental distance,mouth opening,Mafampaii classification,etc.combined with X-ray,computed tomography(CT),and other imaging technologies are mainly used to evaluate difficult airways.However,in many special cases,i.e.,emergency surgery,imaging examinations cannot be completed preoperatively.Such patients’airway can only be evaluated through general physical examination,which inevitably increases the likelihood of an unexpected difficult airway during anesthesia.CASE SUMMARY We report a rare case of difficult intubation because of severe upper trachea distortion after induction.Emergency holmium laser lithotripsy was performed under transurethral ureteroscopy because the patient had anuria for 4 d and a creatinine level of 890μmol/L.Due to the urgency of the condition,chest radiography or chest CT was not examined before surgery and the anesthesiologist did not evaluate the airway adequately,resulting in an unexpected difficult airway.CONCLUSION The incidence of tracheal malformation and tracheal stenosis is extremely low,but the risk of hypoxia and even death due to difficult airways is extremely high for such patients.It is recommended to complete preoperative imaging examinations of the airway.For life-threatening emergency patients,a pre-anesthesia reassessment should be performed and surgeons should be prepared to prevent and manage the difficult airway.

Subcutaneous angiolipoma in the scrotum: A case report

BACKGROUND Angiolipoma has been reported in many cases,and it often occurs in the skin of the trunk and limbs.However,angiolipoma in the scrotum is a rare disease with unknown etiology.This condition is difficult to diagnosis with other lumps in the scrotum.CASE SUMMARY A 32-year-old man presented to the urinary department with a history of an enlarged left scrotum with increasing discomfort for about 5 years.Physical examination revealed that there were a palpable mass measuring about 7.0 cm×6.5 cm in the left scrotum,with smooth surfaces but without tenderness or adhesion to the skin.Ultrasound showed that there was a hyperechoic mass under the skin of the top scrotum,about 72 mm×64 mm×21 mm in size,with clear borders,uneven internal echo,and abundant blood flow signals.Serum human chorionic gonadotropin and alpha-fetoprotein were in normal level.Subcutaneous mass resection at the bottom of the left scrotum was performed under local anesthesia with 1%lidocaine.Postoperative pathological examination resulted in a diagnosis of subcutaneous angiolipoma of the scrotum.No evidence of recurrence was found at 6 mo after surgery and there were no complaints of discomfort.CONCLUSION Angiolipoma is an extremely rare type of benign tumor extremely rarely found in the scrotum,but needs to be considered when evaluating scrotal masses especially when the mass is solid.According to the characteristics of angiolipoma,surgical resection is the best treatment strategy and it is not prone to recurrence after resection.

Aging phenomena of backsheet materials of photovoltaic systems for future zero-carbon energy and the improvement pathway

The insulation degradation in polymeric backsheets has been identified as a main cause of catastrophic accidents induced by short circuit or ground faults in photovoltaic module.To ensure quality,the photovoltaic industry is therefore faced with urgent demand in discovering degradation mechanisms.Moreover,the development of environmental-friendly backsheets and the establishment of backsheets recycling specifications are vital to fulfilling the requirements of a future reliable photovoltaic system with improved productivity.In this review,we innovatively summarize the detection methods of insulation deterioration from the viewpoints of spectroscopic,thermal and mechanical approaches.The corresponding ambient conditions in measurement and their accelerating effect on the degradation of photovoltaic backsheets are discussed.Subsequently,emerging novel materials and structures for enhancing insula-tion properties,antiaging performance and optical-electrical energy conversion efficiency of photovoltaic cell are summarized.It offers a comprehensive strategy to design materials with optimal structures in photovoltaic module for a future zero-carbon energy system.

Using simulated Tianqin gravitational wave data and electromagnetic wave data to study the coincidence problem and Hubble tension problem

In this study,we used electromagnetic wave data(H0LiCOW,H(z),SNe)and gravitational wave data(Tianqin)to constrain the interacting dark energy(IDE)model and investigate the Hubble tension and coincidence problems.By combining these four types of data(Tianqin+HQLiCOW+SNe+H(z)),we obtained the following para-meter values with a confidence interval of 1σ:Ω_(m)=0.36+0.18,ω_(x)=-1.29^(+0.61)_(-0.23)+0.61,ξ=3.15^(+0.36)_(-1.1),and H_(0)=70.04+0.42 kms^(-1) Mpc^(-1).According to our results,the best value of Ho shows that the Hubble tension problem can be al-leviated to some extent.In addition,the center value of ξ+3ω_(x)=-0.72_(-1.19)^(2.19)(1σ)indicates that the coincidence problem is slightly alleviated.However,ξ+3ω_(x)=0 is still within the 1σ error range,which indicates that the ACDM model is still the model in best agreement with the observational data at present.Finally,we compared the constraint results of the electromagnetic and gravitational waves on the model parameters and found that the con-straint effect of electromagnetic wave data on model parameters is better than that of simulated Tianqin gravitational wave data.

卟啉衍生物及其高分子材料

卟啉是一类由4个吡咯环通过次甲基相连而形成的共轭大环化合物.卟啉及其衍生物广泛存在于生物体内,参与催化、氧的输运和能量转移等重要生理过程.因其独特的生理功能和物理化学特性,卟啉衍生物及其高分子材料的制备和合成引起了广泛关注.本文介绍了卟啉及其衍生物在生命系统中的功能及其合成方法,回顾了含卟啉的高分子材料和超分子组装体的设计和制备方法,总结了近年来基于卟啉的高分子和超分子功能材料的研究动态.

基于动态硼酸酯键的水凝胶的模块化组装和智能形变

将苯硼酸基团引入水凝胶网络中,以聚乙烯醇(PVA)为胶水,在碱性条件下通过水凝胶表面与PVA形成动态硼酸酯键,实现了含有苯硼酸基团的水凝胶的模块化组装.通过显微红外表征,证明了在2块水凝胶界面形成了硼酸酯键,并且组装后的水凝胶黏合强度大于水凝胶本体.随后引入聚阳离子单体甲基丙烯酰氧乙基三甲基氯化铵(METAC)以及N-异丙基丙烯酰胺(NIPAm)实现了双层水凝胶的离子与温度双重刺激响应,并且通过胶水黏合位置的选择,实现了二维与三维复杂形变.最后通过刺激响应的双重正向叠加制备了抓取力可调的软机械夹具.

超分子形状记忆水凝胶研究进展

超分子形状记忆水凝胶(SSMHs)是一类利用超分子作用或动态共价键作为分子开关来固定临时形状,并能在特定的刺激下恢复初始形状的高分子水凝胶.本文简要介绍了SSMHs的定义和发展历程,总结了利用不同种类的可逆作用构建SSMHs的最新进展,并扩展介绍了具有多重形状记忆效应和多功能的SSMHs.最后,也对SSMHs所面临的挑战和未来发展方向进行了讨论.

离子印染可控的荧光水凝胶用于多维度信息存储（英文）

本文通过离子印染的方式,赋予荧光水凝胶信息,并将其用于逐级、多维度信息存储.通过铁离子的引入,荧光水凝胶中的芘基团会发生荧光淬灭,在紫外灯下可用于二维平面的信息存储;同时,铁离子的扩散会赋予水凝胶各向异性的结构,使得其在水中驱动得到三维的信息.并且,储存的二维、三维信息可以通过氢离子取代铁离子进行擦除,这使得材料具有很好的可重复利用性.总之,本文为新型柔性信息存储装置的设计和制备提供了新的思路.

Knockdown of OLA1,a regulator of oxidative stress response,inhibits motility and invasion of breast cancer cells

To explore the role of a novel Obg-like ATPase 1 (OLA1) in cancer metastasis,small interference RNA (siRNA) was used to knockdown the protein,and the cells were subjected to in vitro cell migration and invasion assays. Knockdown of OLA1 significantly inhibited cell migration and invasion in breast cancer cell line MDA-MB-231. The knockdown caused no changes in cell growth but affected ROS production. In wound-healing assays,decreased ROS in OLA1-knockdown cells were in situ associated with the cells’ decreased motile morphology. Further,treatment of N-acetylcysteine,a general ROS scavenger,blunted the motility and invasiveness of MDA-MB-231 cells,similar to the effect of OLA1-knockdown. These results suggest that knockdown of OLA1 inhibits breast cancer cell migration and invasion through a mechanism that involves the modulation of intracellular ROS levels.

Proliferating cell nuclear antigen(PCNA)overexpression in hepatocellular carcinoma predicts poor prognosis as determined by bioinformatic analysis

To the Editor:Nowadays,many methods have been taken in early diagnosis and clinical therapy,but the overall survival(OS)of hepatocellular carcinoma(HCC)patients remains unsatisfactory.[1]Therefore,it is seriously significant to identify novel prognostic biomarkers and better to find the promising therapeutic targets.

ST13,a proliferation regulator,inhibits growth and migration of colorectal cancer cell lines

Background and objective:ST13, is the gene encoding the HSP70 interacting protein (HIP). Previous research has shown that ST13 mRNA and protein levels are down-regulated in colorectal cancer (CRC) tissues compared with adjacent normal tissues. This study aims at the role of ST13 in the proliferation and migration of CRC cells. Methods:The transcript level of ST13 in different CRC cell lines was evaluated by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). ST13-overexpressed and ST13-knockdown CRC cells were constructed respectively by lentiviral transduction, followed by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay, plate colony formation, cell-cycle analysis, and migration assays to evaluate the influence of ST13 on proliferation and migration in vitro. Moreover, a mouse xenograft study was performed to test in vivo tumorigenicity of ST13-knockdown CRC cells. Results: Lentivirus-mediated overexpression of ST13 in CRC cells in-hibited cell proliferation, colony formation, and cell migration in vitro. In contrast, down-regulation of ST13 by lentiviral-based short hairpin RNA (shRNA) interference in CRC cells significantly increased cell proliferation and cloning efficiency in vitro. In addition, down-regulation of ST13 expression significantly increased the tumorigenicity of CRC cells in vivo. Conclusions:ST13 gene is a proliferation regulator that inhibits tumor growth in CRC and may affect cell migration.

An Improved Algorithm for Fixed-Hub Single Allocation Problems

This paper discusses the fixed-hub single allocation problem(FHSAP).In this problem,a network consists of hub nodes and terminal nodes.Hubs are fixed and fully connected;each terminal node is assigned to a single hub which routes all its traffic.The goal is to minimize the cost of routing the traffic in the network.In this paper,we propose a new linear programming(LP)relaxation for this problem by incorporating a set of validity constraints into the classical formulations by Ernst and Krishnamoorthy(Locat Sci 4:139–154,Ann Op Res 86:141–159).A geometric rounding algorithm is then used to obtain an integral solution from the fractional solution.We show that by incorporating the validity constraints,the strengthened LP often provides much tighter upper bounds than the previous methods with a little more computational effort and the solution obtained often has a much smaller gap with the optimal solution.We also formulate a robust version of the FHSAP and show that it can guard against data uncertainty with little costs.

Suppression of top-up injection backgrounds with offline event filter in the BESIII experiment

Background It is imperative that high-quality data should be accumulated to guarantee the correctness and accuracy of physics results in particle physics experiments.The top-up injection of BEPCII has achieved a definite improvement in integrated luminosity,but simultaneously has an obvious impact on the background level of the data acquired by the BESIII detector due to frequent beam injections.Methods An online trigger veto and an offline eventfilter have been developed and applied to eliminate the contaminated events from the data samples for physics research.Results and Conclusion The design and implementation of offline eventfilter are described in this article.The upgraded offline data processing procedure with offline eventfilter was executed smoothly in recent years and ensured data acquisition and processing with optimal efficiency and sufficient quality in BESIII experiment.

Endoscopic management of delayed bleeding after polypectomy of small colorectal polyps:two or more clips may be safe

Background:The resection of small colorectal polyps(≤10mm)is routine for endoscopists.However,the management of one of its main complications,namely delayed(within 14 days)postpolypectomy bleeding(DPPB),has not been clearly demonstrated.We aimed to assess the role of coloscopy in the management of DPPB from small colorectal polyps and identify the associated factors for initial hemostatic success.Methods:We conducted a retrospective study of 69 patients who developed DPPB after the removal of colorectal polyps of≤10mmand underwent hemostatic colonoscopy at the Sixth Affiliated Hospital of Sun Yat-sen University(Guangzhou,China)between April 2013 and June 2021.Demographics,clinical variables,and colonoscopic features were collected independently.We applied univariate and multivariate analyses to assess factors associated with initial hemostatic success.Results:General colonoscopy without oral bowel preparation was successfully performed in all the patients,with a median duration of 23.9(12.5–37.9)minutes.Among 69 patients,62(89.9%)achieved hemostasis after initial hemostatic colonoscopy and 7(10.1%)rebled 2.761.1 days after initial colonoscopic hemostasis and had rebleeding successfully controlled by one additional colonoscopy.No colonoscopy-related adverse events occurred.Multivariate analysis showed that management with at least two clips was the only independent prognostic factor for initial hemostatic success(odds ratio,0.17;95%confidence interval,0.03–0.91;P=0.04).All the patients who had at least two clips placed at the initial hemostatic colonoscopy required no further hemostatic intervention.Conclusions:Colonoscopy is a safe,effective,and not too time-consuming approach for the management of patients with DPPB of small colorectal polyps and management with the placement of at least two hemoclips may be beneficial.