Recent Strategies and Advances in Hydrogel‑Based Delivery Platforms for Bone Regeneration

Bioactive molecules have shown great promise for effectively regulating various bone formation processes,rendering them attractive therapeutics for bone regeneration.However,the widespread application of bioactive molecules is limited by their low accumulation and short half-lives in vivo.Hydrogels have emerged as ideal carriers to address these challenges,offering the potential to prolong retention times at lesion sites,extend half-lives in vivo and mitigate side effects,avoid burst release,and promote adsorption under physiological conditions.This review systematically summarizes the recent advances in the development of bioactive molecule-loaded hydrogels for bone regeneration,encompassing applications in cranial defect repair,femoral defect repair,periodontal bone regeneration,and bone regeneration with underlying diseases.Additionally,this review discusses the current strategies aimed at improving the release profiles of bioactive molecules through stimuli-responsive delivery,carrier-assisted delivery,and sequential delivery.Finally,this review elucidates the existing challenges and future directions of hydrogel encapsulated bioactive molecules in the field of bone regeneration.

Molecular Epidemiology and Clinical Characteristics of Hand, Foot and Mouth Disease in North Sichuan Region, China, 2018-2023: A Descriptive Study

Background: Hand, foot and mouth disease (HFMD) remains an important public health problem in China. Many studies on the epidemiological characteristics of HFMD have been reported, but studies in North Sichuan region have been neglected. Methods: HFMD-related enterovirus infected cases were clinically confirmed and underwent real-time RT-PCR (rRT-PCR) from May 2018 to October 2023 in Guangyuan Central Hospital. Results: During 2018-2023, other EV (437 cases, 81.08%) was the most predominant serotype followed by CV-A16 (94 cases, 17.44%), EV-A71 (8 cases, 1.48%) was the least predominant serotype. Peak infections occurred in July and October. There were no significant differences in gender, age and serotypes. HFMD was concentrated in children under 47 months of age, with the highest incidence in children aged 12 - 23 months and the highest proportion of other EV infections in the whole age group. COVID-19 did not cause significant changes in gender, age and serotype. Overall, there was a significant increase in the proportion of children aged 12 - 23 months infected with CV-A16, and an increase in the proportion of children aged over 36 months infected with other EVs. Conclusions: The incidence of HFMD caused by EV-A71 has decreased significantly, and other EVs have become the main pathogens of HFMD in North Sichuan region in recent years. In the prevention and control of CV-A16, more attention should be paid to children aged 12 - 23 months and the dominant serotype should be closely monitored. Our study highlights the importance of developing of new diagnostic reagents and vaccines for the prevention and control of enterovirus infection. This study for the first time provides insights into district interventions to local conditions.

Heat stress affects mammary metabolism by influencing the plasma flow to the glands

Background Environmental heat stress(HS)can have detrimental effects on milk production by compromising the mammary function.Mammary plasma flow(MPF)plays a crucial role in nutrient supply and uptake in the mam-mary gland.In this experiment,we investigated the physiological and metabolic changes in high-yielding cows exposed to different degrees of HS:no HS with thermal-humidity index(THI)below 68(No-HS),mild HS(Mild-HS,68≤THI≤79),and moderate HS(Mod-HS,79<THI≤88)in their natural environment.Our study focused on the changes in blood oxygen supply and mammary glucose uptake and utilization.Results Compared with No-HS,the MPF of dairy cows was greater(P<0.01)under Mild-HS,but was lower(P<0.01)in cows under Mod-HS.Oxygen supply and consumption exhibited similar changes to the MPF under different HS,with no difference in ratio of oxygen consumption to supply(P=0.46).The mammary arterio-vein differences in glucose concentration were lower(P<0.05)under Mild-and Mod-HS than under no HS.Glucose supply and flow were significantly increased(P<0.01)under Mild-HS but significantly decreased(P<0.01)under Mod-HS compared to No-HS.Glucose uptake(P<0.01)and clearance rates(P<0.01)were significantly reduced under Mod-HS compared to those under No-HS and Mild-HS.Under Mild-HS,there was a significant decrease(P<0.01)in the ratio of lac-tose yield to mammary glucose supply compared to that under No-HS and Mod-HS,with no difference(P=0.53)in the ratio of lactose yield to uptaken glucose among different HS situations.Conclusions Degrees of HS exert different influences on mammary metabolism,mainly by altering MPF in dairy cows.The output from this study may help us to develop strategies to mitigate the impact of different degrees of HS on milk production.

Qualitative exploration of home life experiences and care needs among elderly patients with temporary intestinal stomas

BACKGROUND This study employed a phenomenological research approach within qualitative research to explore the challenges encountered by elderly individuals with temporary colostomies in managing their daily lives and care needs.Protecting the anus surgery combined with temporary colostomy has emerged as a prevalent treatment modality for low rectal cancer.However,the ileostomy is susceptible to peri-stoma skin complications,as well as fluid,electrolyte,and nutritional imbalances,posing challenges to effective management.The successful selfmanagement of patients is intricately linked to their adjustment to temporary colostomy;nonetheless,there remains a dearth of research examining the factors influencing self-care among temporary colostomy patients and the obstacles they confront.AIM To investigate the lived experiences,perceptions,and care requirements of temporary colostomy patients within their home environment,with the ultimate goal of formulating a standardized management protocol.METHODS Over the period of June to August 2023,a purposive sampling technique was utilized to select 12 patients with temporary intestinal stomas from a tertiary hospital in Shanghai,China.Employing a phenomenological research approach,a semi-structured interview guide was developed,and qualitative interviews were conducted using in-depth interview techniques.The acquired data underwent coding,analysis,organization,and summarization following Colaizzi’s seven-step method.RESULTS The findings of this study revealed that the experiences and needs of patients with temporary intestinal stomas can be delineated into four principal themes:Firstly,Temporary colostomy patients bear various burdens and concerns about the uncertainty of disease progression;secondly,patients exhibit limited self-care capabilities and face information deficits,resulting in heightened reliance on healthcare professionals;thirdly,patients demonstrate the potential for internal motivation through proactive self-adjustment;and finally,patients express a significant need for emotional and social support.CONCLUSION Home-living patients with temporary intestinal stomas confront multifaceted challenges encompassing burdens,inadequate self-care abilities,informational deficits,and emotional needs.Identifying factors influencing patients’self-care at home and proposing strategies to mitigate barriers can serve as a foundational framework for developing and implementing nursing interventions tailored to the needs of patients with temporary intestinal stomas.

Factors influencing the continuity of evidence-based practice in perioperative airway management for elderly patients with fractures:A qualitative study

BACKGROUND More and more evidence-based practices are emerging,but researchers mostly focus on short-term effects,resulting in evidence-based practices not being applied in the clinic in the long term.In this study,we took the evidence-based practice of perioperative airway management in elderly fracture patients as an example and adopted a descriptive phenomenological approach to understand the influencing factors of its sustainability to provide a reference basis for promoting the continuity of evidence-based practice in the clinic.AIM To explore factors influencing the persistence of evidence-based practice in perioperative airway management in elderly patients with fractures.METHODS This study was qualitative research.Nine nurses who implemented evidencebased practice in the orthopedic ward of a tertiary comprehensive hospital in Shanghai from September 2023 to October 2023 were selected using purposive sampling as research subjects.Semi-structured interviews were conducted with them,and the data were analyzed using the Colaizzi phenomenological analysis method based on the three dimensions and ten factors of the NHS sustainability model.RESULTS Three main themes and ten subthemes were identified:Process aspects(benefits to patients,benefits to nurses,lack of follow-up,complex processes);staff aspects(insufficient human resources,inadequate training and education,lack of leadership support);and organizational environment aspects(inadequate infrastructure,poor patient compliance,poor doctor cooperation).CONCLUSION Human resources,training and education,leadership support,infrastructure,and patient-physician collaboration are important factors influencing the sustainability of evidence-based practice for perioperative airway management in older patients with fractures.

Medical appraisal of Chinese military aircrew with abnormal results of coronary computed tomographic angiography

BACKGROUND Coronary artery diseases can cause myocardial ischemia and hypoxia,angina pectoris,myocardial infarction,arrhythmia,and even sudden death led to inflight incapacitation of aircrew.As the main cause of grounding due to illness,they severe threats to the health and fighting strength of military aircrew.Early warning in an early and accurate manner and early intervention of diseases possibly resulting in inflight incapacitation are key emphases of aeromedical support in clinic.AIM To figure out the flight factors and clinical characteristics of military aircrew with abnormal results of coronary artery computed tomographic angiography(CTA),thereby rendering theoretical references for clinical aeromedical support of military flying personnel.METHODS The clinical data of 15 flying personnel who received physical examinations in a military medical center from December 2020 to June 2023 and were diagnosed with coronary artery diseases by coronary artery CTA were collected and retrospectively analyzed,and a descriptive statistical analysis was conducted on their onset age,aircraft type and clinical data.RESULTS The 15 military flying personnel diagnosed with coronary artery diseases by coronary artery CTA were composed of 9 pilots,1 navigator and 5 air combat service workers.Multi-vessel disease was detected in 9 flying personnel,among which 8(88.9%)were pilots.Flying personnel with multi-vessel disease had higher content of cholesterol,low-density lipoprotein cholesterol and apolipoprotein B than those with single-vessel disease.CONCLUSION Coronary artery diseases are the major heart disease for the grounding of flying personnel due to illness,which can lead to inflight incapacitation.Coronary artery CTA is conducive to early detection and early intervention treatment of such diseases in clinic.

Spectra of intracranial diseases in Chinese military pilots(cadets)unqualified for transfer to pilot modified high performance aircraft

BACKGROUND With very high mortality and disability rates,cerebrovascular diseases and intracranial tumors severely threaten the health and fighting strength of flying personnel,requiring great concern and intensive screening in clinic,early warning in an early and accurate manner and early intervention of diseases possibly resulting in inflight incapacitation are key emphases of aeromedical support in clinic.AIM To probe into the spectra of intracranial diseases,flight factors and medical imaging characteristics of military pilots(cadets)in the physical examination for transfer to pilot modified high performance aircraft,thus rendering theoretical references for clinical aeromedical support of pilots.METHODS A total of 554 military pilots(cadets)undergoing physical examination for transfer to pilot modified high performance aircraft from December 2020 to April 2024 in a military medical center were enrolled in this study.Then,a retrospective study was carried out on intracranial disease spectra and head magnetic resonance imaging(MRI)data of 36 pilots(cadets)who were unqualified for transfer to pilot modified high performance aircraft.Besides,a descriptive statistical analysis was conducted on the clinical data,age,fighter type and head MRI data of such pilots(cadets).RESULTS Abnormal head images were found in 36 out of 554 pilots(cadets)participating in the physical examination for transfer to pilot modified high performance aircraft,including arachnoid cyst in 17(3.1%)military pilots(cadets),suspected very small aneurysm in 11(2.0%),cavernous hemangioma in 4(0.7%),vascular malformation in 2(0.4%),and pituitary tumor in 3(0.5%,one of which developed cavernous hemangioma simultaneously).Among the 17 pilots(cadets)with arachnoid cyst,4 were identified as unqualified for transfer to pilot modified high performance aircraft because the marginal brain tissues were compressed by the cyst>6 cm in length and diameter.The 11 pilots(cadets)with suspected very small aneurysms identified by 3.0T MRI consisted of 6 diagnosed with conus arteriosus by digital subtraction angiography and qualified for transfer to pilot modified high performance aircraft,and 5 identified as very small intracranial aneurysms with diameter<3 mm and unqualified for transfer to pilot modified high performance aircraft.No symptoms and signs were observed in the 4 military pilots(cadets)with cavernous hemangioma,and the results of MRI revealed bleeding.The 1 of the 4 had the lesion located in pons and developed Rathke cyst in pituitary gland at the same time,and unqualified for transfer to pilot modified high performance aircraft.The 2 of the 4 were unqualified for flying,and 2 transferred to air combat service division.The 2 pilots(cadets)with vascular malformation were identified as unqualified for transfer to pilot modified high performance aircraft.Among the 3 pilots(cadets)with pituitary tumor,one pilot cadet was identified as unqualified for flying since the tumor compressed the optic chiasma,one had cavernous hemangioma in pons in the meantime and transferred to air combat service division,and one was diagnosed with nonfunctional microadenoma and qualified for transfer to pilot modified high performance aircraft.CONCLUSION High-resolution head MRI examination is of great significance for screening and detecting cerebrovascular diseases and intracranial tumors in military flying personnel,and attention should be paid to its clinical application to physical examination for transfer to pilot modified high performance aircraft.

Bone mesenchymal stem cell-derived exosomes involved co-delivery and synergism effect with icariin via mussel-inspired multifunctional hydrogel for cartilage protection

Mesenchymal stem cells(MSC)are particularly effective in promoting cartilage regeneration due to their immunomodulatory,anti-inflammatory and regenerative repair functions of tissues and organs.Meanwhile,the intra-articular delivery and synergy with other therapeutic drugs have been the key issues driving their further application.We report a mussel-inspired multifunctional hydrogel system,which could achieve co-delivery and synergism effect of MSC-derived exosomes(Exos)with icariin(ICA).The ICA and Exos co-delivered articular cavity injection system are expected to retain in the joint cavity and promote cartilage regeneration,due to the thermosensitive,self-healing and adhesion properties of the mussel-inspired multifunctional hydrogel.The experimental results proved that Exos enhanced the cellular uptake of ICA by more than 2-fold evenly,and the synergism of Exos and ICA efficiently improve the cell proliferation and migration.After synergic treatment,the content of matrix metalloproteinase 13 in the supernatant and intracellular decreased by 47%and 59%,respectively.In vivo study,ICA-loaded Exos exhibited prolonged retention behavior bymultifunctional hydrogel delivery,thus displayed an increased cartilage protection.In the model of osteoarthritis,co-delivery hydrogel system relieved the cartilage recession,ensuring appropriate cartilage thickness.

Modeling for UAV resource scheduling under mission synchronization

Unmanned aerial vehicle（UAV） resource scheduling means to allocate and aggregate the available UAV resources depending on the mission requirements and the battlefield situation assessment.In previous studies,the models cannot reflect the mission synchronization;the targets are treated respectively,which results in the large scale of the problem and high computational complexity.To overcome these disadvantages,a model for UAV resource scheduling under mission synchronization is proposed,which is based on single-objective non-linear integer programming.And several cooperative teams are aggregated for the target clusters from the available resources.The evaluation indices of weapon allocation are referenced in establishing the objective function and the constraints for the issue.The scales of the target clusters are considered as the constraints for the scales of the cooperative teams to make them match in scale.The functions of the intersection between the ＂mission time-window＂ and the UAV ＂arrival time-window＂ are introduced into the objective function and the constraints in order to describe the mission synchronization effectively.The results demonstrate that the proposed expanded model can meet the requirement of mission synchronization,guide the aggregation of cooperative teams for the target clusters and control the scale of the problem effectively.

AIGC Scenario Analysis and Research on Technology Roadmap of Internet Industry Application

The explosion of ChatGPT is considered to be a milestone in the normalization of artificial intelligence education applications.On the technical line,the cross-modal AI generation application based on human feedback system is accelerated.In the business model,the scenes to realize interactive functions are constantly enriched.This paper reviews the evolution process of AIGC,closely follows the current situation of the coexistence of business acceleration and technical worries in the application of artificial intelligence education,analyzes the application of AIGC education in 7 subdivided fields,and analyzes the optimization direction of application cases from the perspective of perception-cognition-creation technology maturity matrix.The 3 recommendations and 2 follow-up research directions will promote the scientific application of artificial intelligence education in the AIGC period.

Clinical efficacy of tocilizumab treatment in severe and critical COVID-19 patients

BACKGROUND The main pathophysiological basis of coronavirus disease 2019(COVID-19)causing respiratory failure is a cytokine storm and interleukin-6(IL-6)is an important component of the COVID-19 cytokine storm.As a specific antagonist of IL-6,tocilizumab may block the cytokine storm of COVID-19.The Diagnosis and Treatment Guidelines of New Coronavirus Pneumonia(7 th Edition)includes tocilizumab as a recommended drug for immunotherapy in severe and critical COVID-19 patients.However,the specific clinical efficacy of tocilizumab in the treatment of COVID-19 patients is worth studying.AIM To determine the clinical efficacy of tocilizumab in inhibiting the cytokine storm in COVID-19.METHODS In total,19 severe and critical COVID-19 patients were enrolled in this study,and were treated with tocilizumab in Optical Valley Campus of Hubei Maternal and Child Health Care Hospital from February 20 to March 31,2020.The imaging manifestations and clinical data before and after treatment were analyzed retrospectively,including routine peripheral venous blood tests,routine blood biochemical tests,coagulation test,C-reactive protein(CRP),IL-6,and arterial blood gas analysis.RESULTS Of the 19 patients in this group,13(68.4%)had significantly improved symptoms of COVID-19(5 patients were discharged directly and 8 patients were transferred after improvement)following treatment.One case was invalid,1 case was exacerbated,and 4 deaths(21.1%)were observed(all critical cases).The lymphocyte count,CRP,lactic acid,oxygenation index,fibrinogen(FIB)and IL-6 levels were significantly different in the improved group.CONCLUSION Tocilizumab treatment is effective against IL-6 in COVID-19 patients,but it does not completely inhibit the inflammation and cytokine storm in all patients with COVID-19.In the clinical treatment of COVID-19 patients,attention should be paid to the timing of drug administration and other adjuvant treatments.

Heat stress affects dairy cow health status through blood oxygen availability

Background Rises in global warming and extreme weather occurrence make the risk of heat stress(HS)induced by high ambient temperatures more likely in high-yielding dairy cows,resulting in low milk quality and yield.In ani-mals,oxygen is involved in many physiological and metabolic processes,but the effects of HS on oxygen metabolism remain unclear.Thus,the current study aimed to investigate how oxygen metabolism plays a role in health status of dairy cows by measuring the milk yield,milk composition,and blood biochemical variables of cows under different levels of HS:none(No-HS),mild(Mild-HS),and moderate HS(Mod-HS).Results The HS significantly increased rectal temperature(Ptreat<0.01)and respiration rate(Ptreat<0.01).Under Mod-HS,greater Na+(P<0.05)and lower total CO_(2),and pH(P<0.05)were observed relative to those under No-HS and Mild-HS.Oxygen concentrations in both coccygeal artery and mammary vein(Ptreat<0.01)were lower under Mod-HS than under No-HS.Coccygeal vein concentrations of heat shock protein 90(HSP90)(P<0.05)increased during Mod-HS compared with those in cows under No-HS.Malondialdehyde increased during Mod-HS,and glu-tathione peroxidase(P<0.01)increased during Mild-HS.Coccygeal vein concentrations of vascular endothelial growth factor(P<0.01),heme oxygenase-1(P<0.01),and hypoxia-inducible factor 1α(P<0.01)were greater in cows under Mod-HS than those under No-HS.Red blood cell count(P<0.01)and hemoglobin concentration(P<0.01)were lower in the coccygeal vein of dairy cows under Mild-and Mod-HS than those of cows under No-HS.Conclusions Exposure to HS negatively impacts the health status and lactation performance of dairy cows by limit-ing oxygen metabolism and transportation.However,the specific mechanism by which HS affects mammary function in cows remains unclear and requires further exploration.

黄素依赖型卤化酶的研究进展及应用

卤化物在医药化工领域有着不可替代的地位,然而传统的有机化学卤代反应因其严苛的反应条件和高毒性而限制了推广应用。随着生物化学中酶反应的发展,卤代酶以高效率条件温和的特点被逐渐重视起来。在已发现的各类不同种类以及各样作用机理的卤代酶中,黄素依赖型卤代酶(flavin-dependent halogenases)具有良好的底物特异性以及稳定的催化位点选择性。而通过对蛋白结构的研究以及突变改进酶的特性,这类卤代酶被证明可以用于工业生产以及药物开发。尽管目前对于黄素依赖型的研究正处于起步阶段,但其广泛的分布性以及稳定可控的特性给未来的应用带来光明的前景。

Clinical diagnosis,treatment,and medical identification of specific pulmonary infection in naval pilots:Four case reports

BACKGROUND Specific pulmonary infection could seriously threaten the health of pilots and their companions.The consequences are serious.We investigated the clinical diagnosis,treatment,and medical identification of specific pulmonary infections in naval pilots.CASE SUMMARY We analyzed the medical waiver and clinical data of four pilots with specific pulmonary infections,who had accepted treatment at the Naval Medical Center of Chinese People’s Liberation Army between January 2020 and November 2021,including three cases of tuberculosis and one of cryptococcal pneumonia.All cases underwent a series of comprehensive treatment courses.Three cases successfully obtained medical waiver for flight after being cured,while one was grounded after reaching the maximum flight life after being cured.CONCLUSION Chest computed tomography scanning should be used instead of chest radiography in pilots’physical examination.Most pilots with specific pulmonary infection can be cured and return to flight.

Analysis of two naval pilots’ ejection injuries: Two case reports

BACKGROUND Recently,two naval pilots in a two-seat trainer jet were forced to eject urgently due to sudden mechanical failure during night-time training.They were both successfully rescued and sent to the hospital for emergency treatment.In this study,we investigate their ejection injuries and recovery process.CASE SUMMARY We analyzed the clinical data of the traumatic condition and recovery process from ejection injuries of two pilots who ejected from a failed trainer jet and survived.After being successfully rescued and sent to the hospital,they were diagnosed with multiple ejection injuries,including eye trauma,limb bone and joint injury,rib and spine injury,and so on.Both cases underwent fluid replacement,acid suppression,nutritional support,hemostasis,bone metabolism improvement,phlegm elimination,psychological measurement,blood circulation promotion and detumescence,physical therapy,and external fixation with braces for 1 mo before being discharged from hospital.They then recuperated in a sanatorium for 2 mo,and the related laboratory tests and supplementary examinations show that they recovered from all the above injuries.After successfully passing the psychological test and physical examination,they returned to flight duty 3 mo after ejection.CONCLUSION The causes and conditions of ejection injury in the pilots were very complex.Although they finally recovered quickly and were released,it also serves as a reminder that attention should be paid to pilots’ejection and parachute training in order to significantly reduce ejection injury and improve the ejection success rate.In addition,air defense support personnel should strengthen search and rescue and on-site emergency measures,and locate and rescue pilots in distress as early as possible to reduce subsequent injuries.

Retrospective analysis of influencing factors on the efficacy of mechanical ventilation in severe and critical COVID-19 patients

BACKGROUND The novel coronavirus disease 2019(COVID-19)has spread widely around the world with strong infectivity,rapid mutation and a high mortality rate.Mechanical ventilation has been included in the Diagnosis and Treatment Protocol for Novel Coronavirus Pneumonia(Trial Version 8)as an important treatment for severe and critical COVID-19 patients,but its clinical efficacy in COVID-19 patients is various.Therefore,it is necessary to study the influencing factors on the efficacy of mechanical ventilation in severe and critical COVID-19 patients.AIM The aim of this study was to determine the influencing factors on the efficacy of mechanical ventilation in severe and critical COVID-19 patients.METHODS A total of 27 severe and critical COVID-19 patients were enrolled in this study and treated with mechanical ventilation at the Optical Valley Campus of Hubei Maternal and Child Health Care Hospital(Wuhan,Hubei Province)from February 20,2020 to April 5,2020.According to the final treatment outcomes,the patients were divided into the“effective group”and“death group.”The clinical data of the two groups,such as the treatment process and final outcome,were retrospectively analyzed in order to determine the specific curative effects on the two groups and the reasons for the differences in such curative effects,as well as to explore the factors related to death.RESULTS This study enrolled 27 severe and critical COVID-19 patients,including 17 males(63.0%)and 10 females(37.0%).Their ages were 74.41±11.73-years-old,and 19 patients(70.4%)were over 70-years-old.Severe COVID-19 patients over 70-yearsold who were treated with mechanical ventilation died in 14 cases(82.4%);thus,this was the peak age.A total of 17 patients died of basic disease,16 of whom had more than two basic diseases.The basic diseases were hypertension,diabetes,and cardiovascular and cerebrovascular diseases.At the same time,13 patients(76.5%)died from an abnormal increase in blood glucose.Among them,eight had diabetes before contracting COVID-19 and five had a stress-induced increase in blood glucose after contracting COVID-19.Diabetic ketoacidosis occurred in one case.The use of tocilizumab may be a double-edged sword that carries a certain risk in clinical usage.Among the patients who died,16(94.1%)went into septic shock at the end.There were significant differences in the degree of infection,cardiac and renal function,and blood glucose between the death group and effective group.CONCLUSION Age,blood glucose,cardiac and renal function,and inflammatory reaction are important indicators of poor prognosis for mechanical ventilation in severe and critical COVID-19 patients.

Reconstructing in vivo spatially offset Raman spectroscopy of human skin tissue using a GPU-accelerated Monte Carlo platform

As one type of spatially offset Raman spectroscopy(SORS), inverse SORS is particularly suited to in vivo biomedical measurements due to its ring-shaped illumination scheme. To explain inhomogeneous Raman scattering during in vivo inverse SORS measurements, the light–tissue interactions when excitation and regenerated Raman photons propagate in skin tissue were studied using Monte Carlo simulation. An eight-layered skin model was first built based on the latest transmission parameters. Then, an open-source platform, Monte Carlo e Xtreme(MCX), was adapted to study the distribution of 785 nm excitation photons inside the model with an inverse spatially shifted annular beam. The excitation photons were converted to emission photons by an inverse distribution method based on excitation flux with spatial offsets Δs of 1 mm, 2 mm, 3 mm and 5 mm. The intrinsic Raman spectra from separated skin layers were measured by continuous linear scanning to improve the simulation accuracy. The obtained results explain why the spectral detection depth gradually increases with increasing spatial offset, and address how the intrinsic Raman spectrum from deep skin layers is distorted by the reabsorption and scattering of the superficial tissue constituents. Meanwhile, it is demonstrated that the spectral contribution from subcutaneous fat will be improved when the offset increases to 5 mm, and the highest detection efficiency for dermal layer spectral detection could be achieved when Δs = 2 mm. Reasonably good matching between the calculated spectrum and the measured in vivo inverse SORS was achieved, thus demonstrating great utility of our modeling method and an approach to help understand the clinical measurements.

自动驾驶开源数据体系:现状与未来

随着自动驾驶技术的不断成熟与应用,系统性梳理开源自动驾驶数据集有利于产业生态良性循环.现有自动驾驶数据集可大致分为两代,第一代数据集的传感模态复杂度相对较低、数据集规模相对较小,且大多局限于感知级任务,以发布于2012年的KITTI为代表.相比于第一代数据集,第二代数据集的特征为传感模态复杂度较高、数据集规模与多样性较丰富、所设置任务从感知扩展到预测、规控上,以2019年前后提出的nuScenes,Waymo为代表.本文联合学术界、产业界同仁,首次系统性梳理了国内外70余种开源自动驾驶数据集,对如何构建高质量数据集、数据在算法闭环体系中发挥的核心作用、如何利用生成式大模型规模化生产数据等进行了总结.此外,就未来第三代自动驾驶数据集应该具备的特质和数据规模,以及需要解决的科学与技术问题,进行了详细分析与讨论.希望本文的归纳与展望能促进新一代自动驾驶数据集与生态体系的建设、推动关键领域自主原创与科技自强的发展.

Particle shape effect on hydrodynamics and heat transfer in spouted bed:A CFD-DEM study

Spouted bed has drawn much attention due to its good heat and mass transfer efficiency in many chemical units.Investigating the flow patterns and heat and mass transfer inside a spouted bed can help optimize the spouting process.Therefore,in this study,the effects of particle shape on the hydrodynamics and heat transfer in a spouted bed are investigated.This is done by using a validated computational fluid dynamics-discrete element method(CFD-DEM)model,considering volume-equivalent spheres and oblate and prolate spheroids.The results are analysed in detail in terms of the flow pattern,microstruc-ture,and heat transfer characteristics.The numerical results show that the prolate spheroids(Ar=2.4)form the largest bubble from the beginning of the spouting process and rise the highest because the fluid drag forces can overcome the interlocking and particle-particle frictional forces.Compared with spherical particles,ellipsoidal spheroids have better mobility because of the stronger rotational kinetic energy resulting from the rough surfaces and nonuniform torques.In addition,the oblate spheroid system exhibits better heat transfer performance benefiting from the larger surface area,while prolate spheroids have poor heat transfer efficiency because of their orientation distribution.These findings can serve as a reference for optimizing the design and operation of complex spouted beds.

Enhancing Nucleation and Detachment of Condensed Drops by Hybrid Wetting Surfaces

Hybrid wetting surfaces have been developed to enhance condensation heat transfer, water collection and seawater desalination, due to the advantages of high droplet nucleation efficiency and excellent removal effect. However, there are still many difficulties to overcome before a simple, operable and low-cost system can be exploited in large-scale practical applications. In the present report, an applicable way to fabricate sprayable hybrid wetting coatings mixed with superhydrophobic and hydrophilic particles is described. Conventional condensation tests are carried out for comparison of the nucleation, growth, coalescence and ejection behaviors of dewdrops on a hybrid wetting surface with different hydrophilic particles. Test results showed that a hybrid wetting surface with superhydrophobic and hydrophilic particles has a higher drop number density than a homogeneous superhydrophobic surface has. As expected, this advantage was exhibited also in the water collection test.