无机及分析化学自主设计实验的探究和实践——以“硫酸四氨合铜(II)的制备及组成分析”为例

从教学改革的角度出发,通过增加自主设计实验来促进学生的自主学习能力和实验设计思维能力的提升。自主设计实验要求学生自主查阅文献、设计实验方案、分析方案可行性、实验探究后进行综合讨论分析。进一步培养学生独立思考、融会贯通的能力,培养查阅文献、撰写实验方案的能力,为将来的科学研究工作打下坚实基础。

以创新人才培养为导向的无机及分析化学实验课程体系建设与实践

以培养创新型人才为出发点,针对一年级本科生在无机及分析化学实验教学中存在的问题,探讨了从“以教为主”转变为“以学为主”的课程体系建设与实施情况。通过优化课程体系、拓展培养模式、强化平台建设等手段,在引导学生主动探究、独立思考、掌握科学研究方法等方面取得了一定的成效。

Real-world effectiveness and safety of goserelin 10.8-mg depot in Chinese patients with localized or locally advanced prostate cancer

Objective:Real-word data on long-acting luteinizing hormone-releasing hormone(LHRH)agonists in Chinese patients with prostate cancer are limited.This study aimed to determine the real-world effectiveness and safety of the LHRH agonist,goserelin,particularly the long-acting 10.8-mg depot formulation,and the follow-up patterns among Chinese prostate cancer patients.Methods:This was a multicenter,prospective,observational study in hormone treatment-na?ve patients with localized or locally advanced prostate cancer who were prescribed goserelin 10.8-mg depot every 12 weeks or 3.6-mg depot every 4 weeks with or without an anti-androgen.The patients had follow-up evaluations for 26 weeks.The primary outcome was the effectiveness of goserelin in reducing serum testosterone and prostate-specific antigen(PSA)levels.The secondary outcomes included testosterone and PSA levels,attainment of chemical castration(serum testosterone<50 ng/d L),and goserelin safety.The exploratory outcome was the monitoring pattern for serum testosterone and PSA.All analyses were descriptive.Results:Between September 2017 and December 2019,a total of 294 eligible patients received≥1 dose of goserelin;287 patients(97.6%)were treated with goserelin 10.8-mg depot.At week 24±2,the changes from baseline[standard deviation(95%confidence interval)]in serum testosterone(n=99)and PSA(n=131)were-401.0 ng/d L[308.4 ng/d L(-462.5,-339.5 ng/d L)]and-35.4 ng/m L[104.4 ng/m L(-53.5,-17.4 ng/m L)],respectively.Of 112 evaluable patients,100(90.2%)achieved a serum testosterone level<50 ng/d L.Treatment-emergent adverse events(TEAEs)and severe TEAEs occurred in 37.1%and 10.2%of patients,respectively.The mean testing frequency(standard deviation)was 1.6(1.5)for testosterone and 2.2(1.6)for PSA.Conclusions:Goserelin 10.8-mg depot effectively achieved and maintained castration and was well-tolerated in Chinese patients with localized and locally advanced prostate cancer.

A developed ant colony algorithm for cancer molecular subtype classification to reveal the predictive biomarker in the renal cell carcinoma

Background:Recently,researchers have been attracted in identifying the crucial genes related to cancer,which plays important role in cancer diagnosis and treatment.However,in performing the cancer molecular subtype classification task from cancer gene expression data,it is challenging to obtain those significant genes due to the high dimensionality and high noise of data.Moreover,the existing methods always suffer from some issues such as premature convergence.Methods:To address those problems,we propose a new ant colony optimization(ACO)algorithm called DACO to classify the cancer gene expression datasets,identifying the essential genes of different diseases.In DACO,first,we propose the initial pheromone concentration based on the weight ranking vector to accelerate the convergence speed;then,a dynamic pheromone volatility factor is designed to prevent the algorithm from getting stuck in the local optimal solution;finally,the pheromone update rule in the Ant Colony System is employed to update the pheromone globally and locally.To demonstrate the performance of the proposed algorithm in classification,different existing approaches are compared with the proposed algorithm on eight high-dimensional cancer gene expression datasets.Results:The experiment results show that the proposed algorithm performs better than other effective methods in terms of classification accuracy and the number of feature sets.It can be used to address the classification problem effectively.Moreover,a renal cell carcinoma dataset is employed to reveal the biological significance of the proposed algorithm from a number of biological analyses.Conclusion:The results demonstrate that CAPS may play a crucial role in the occurrence and development of renal clear cell carcinoma.

混合式教学模式在化学实验室安全课程中的探索与应用

兰州大学化学国家级实验教学示范中心建设的混合式课程"化学实验室安全",通过线上线下相结合的教学模式,建立了集安全培训、虚拟仿真学习、安全考核及准入认证为一体的实验室安全准入课程,构建了立体、系统和联动的安全准入信息管理系统,是高校开展实验室安全教育与考核的有效载体。混合式教学模式的开展推动了学生安全价值观的培育,增强了学生的安全环保意识,提升了实验安全培训效率,对安全素养文化的建设具有积极作用。

以培养创新型人才为导向的基础分析化学实验教学改革的探索与应用

从新时代培养创新型人才的角度出发,阐述了基础分析化学实验教学方法改革的必要性。针对大学基础分析化学实验,提出了从课前预习、课堂讲授、实验指导、课后讨论总结到学期末实验考核方式的具体整改方案。与传统实验教学方法相比,新方法的实施有效提高了学生学习的主动性,培养了学生扎实的实验技能以及创新能力。

Hop-by-hop Content Distribution with Network Coding in Multihop Wireless Networks

The predominant use of today＇s networks is content access and distribution. Network Coding （NC） is an innovative technique that has potential to improve the efficiency of multicast content distribution over multihop Wireless Mesh Networks （WMNs） by allowing intermediate Forwarding Nodes （FNs） to encode and then forward data packets. Practical protocols are needed to realize the benefits of the NC technique. However, the existing NC-based multicast protocols cannot accurately determine the minimum number of coded packets that a FN should send in order to ensure successful data delivery to the destinations, so that many redundant packets are injected into the network, leading to performance degradation. In this paper, we propose HopCaster, a novel reliable multicast protocol that incorporates network coding with hop-by-hop transport. HopCaster completely eliminates the need for estimating the number of coded packets to be transmitted by a FN, and avoids redundant packet transmissions. It also effectively addresses the challenges of heterogeneous mulficast receivers. Moreover, a cross-layer multicast rate adaptation mechanism is proposed, which enables HopCaster to optimize multicast throughput by dynamically adjusting wireless transmission rate based on the changes in the receiver population and channel conditions during the course of mulficasting a coded data chunk. Our evaluations show that HopCaster significantly outperforms the existing NC-based multicast protocols.

Optimal chunk caching in network coding-based qualitative communication

Network processing in the current Internet is at the entirety of the data packet,which is problematic when encountering network congestion.The newly proposed Internet service named Qualitative Communication changes the network processing paradigm to an even finer granularity,namely chunk level,which obsoletes many existing networking policies and schemes,especially the caching algorithms and cache replacement policies that have been extensively explored in Web Caching,Content Delivery Networks(CDN)or Information-Centric Networks(ICN).This paper outlines all the new factors that are brought by random linear network coding-based Qualitative Communication and proves the importance and necessity of considering them.A novel metric is proposed by taking these new factors into consideration.An optimization problem is formulated to maximize the metric value of all retained chunks in the local storage of network nodes under the constraint of storage limit.A cache replacement scheme that obtains the optimal result in a recursive manner is proposed correspondingly.With the help of the introduced intelligent cache replacement algorithm,the performance evaluations show remarkably reduced end-to-end latency compared to the existing schemes in various network scenarios.

Frequent and prolonged nocturnal occupation of port areas by Yangtze finless porpoises (Neophocaena asiaeorientalis): Forced choice for feeding?

During the Yangtze Freshwater Dolphin Expedition 2012,Yangtze finless porpoises(Neophocaena asiaeorientalis)were acoustically monitored in 9 port areas at night.During 6566 min of nocturnal monitoring,porpoise sonar was detected for 488 min(7.43%of the total time).Of all 81 encounters,the longest echolocation span obtained was 102.9 min,suggesting frequent and prolonged porpoise occupation of the port areas.A combined total of 2091 click trains were recorded,with 129(6.2%)containing minimum inter-click intervals(ICIs)below 10 ms(termed a buzz).Buzzes with a decrease in ICIs and search and approach phases that resembled feeding echolocation signals accounted for 44.2%(N=52)of all buzzes.Buzzes with an increase in ICIs,suggesting a mirrored prey capture phase,accounted for 20.2%(N=26)and could reflect attempts to locate escaped prey because they were followed by approach-phase feeding buzzes.Anecdotal evidence of porpoises fleeing the proximity of vessels was observed.The recordings indicating clusters of porpoises feeding near the port areas suggest a forced choice for feeding due to the relatively higher prey availability in the port areas compared to other areas in the Yangtze River that are probably overfished.

A pioneering survey of deep-diving and off-shore cetaceans in the northern South China Sea

A pioneering boat-based survey was conducted in 2019,to gather baseline information regarding the presence,composition,relative abundance,and spatial distribution of deep-diving and off-shore cetaceans in the northern South China Sea(SCS).A total of 27 sightings comprising at least 8 cetacean species were recorded during the 13-day survey,including 5 deep-diving species(i.e.Risso’s dolphin[Grampus griseus],short-finned pilot whale[Globicephala macrorhynchus],sperm whale[Physeter macrocephalus],Cuvier’s beaked whale[Ziphius cavirostris],and an unidentified beaked whale[either the ginkgo-toothed beaked whale,Mesoplodon ginkgodens,or Deraniyagala’s beaked whale,Mesoplodon hotaula]),as well as 3 off-shore dolphins(i.e.pantropical spotted dolphin[Stenella attenuate],striped dolphin[Stenella coeruleoalba],and Fraser’s dolphin[Lagenodelphis hosei]).With the exception of pantropical spotted dolphins,all other species were sighted and recorded at sea in the northern SCS for the first time.The pantropical spotted dolphin was the most frequently sighted species,comprising 30%of the total sightings.Deep-diving cetaceans were mainly sighted in the northern Xisha Archipelago,whereas off-shore dolphins were distributed across the survey area.The pantropical spotted dolphin was observed in aggregations of more than 100 individuals and nearly all encountered species included calves;these findings suggested that the survey area functions as an important feeding and calving ground for various cetacean species.This pioneering survey provides fundamental information regarding cetacean fauna in the northern SCS and highlights the need to strengthen research and conservation efforts concerning these species.

First live sighting of Deraniyagala’s beaked whale(Mesoplodon hotaula)or ginkgo-toothed beaked whale(Mesoplodon ginkgodens)in the western Pacific(South China Sea)with preliminary data on coloration,natural markings,and surfacing patterns

Beaked whales represent around 25%of known extant cetacean species,yet they are the least known of all marine mammals.Identification of many Mesoplodon species has relied on examination of a few stranded individuals.Particularly,the ginkgo-toothed beaked whale(Mesoplodon ginkgodens)and Deraniyagala’s beaked whale(Mesoplodon hotaula)are among the least-known of beaked whale species,without confirmed sightings of living individuals to date.We present a sighting of 3 free-ranging individuals of M.ginkgodens/hotaula whale from a dedicated marine mammal vessel survey carried out in the South China Sea in April and May 2019.Photographic data(301 photographs)from the sighting were compared to photos of fresh stranded ginkgo-toothed beaked whale and Deraniyagala’s beaked whale from both historical and unpublished records.We found that free-ranging M.ginkgodens and M.hotaula individuals can be easily distinguished from other Mesoplodon species due to differences in melon and gape shapes and coloration patterns.However,accurate at-sea differentiation of M.ginkgodens and M.hotaula may not be possible due to high similarity in both coloration and scarring patterns.In addition to our photo-identification data,we collected what we believe to be the first preliminary descriptions of surfacing behavior and diving patterns of one of these species.Finally,the presence of scars possibly caused by fishing gear or marine litter raises concerns about anthropogenic impacts and conservation of these poorly known species.

Potential impacts of shipping noise on Indo-Pacific humpback dolphins and implications for regulation and mitigation:a review

Shipping noise is a widespread and relatively loud sound source among human-induced underwater sounds.The impacts of shipping noise are of special concern for Indo-Pacific humpback dolphins(Sousa chinensis),as they inhabit shallow and nearshore habitats and are highly dependent on sound for survival.This study synthesizes our current understanding of the potential impacts of shipping noise on Indo-Pacific humpback dolphins combined with knowledge on sound production and hearing of these animals and the impacts of noise on other whales and dolphins.For further protection and management of Indo-Pacific humpback dolphins and their habitats,shipping noise should be regulated and mitigated to modify sound from ships,to reduce overall noise levels,and to set more marine protected areas(MPAs)covering most Indo-Pacific humpback dolphin habitats with seasonal and geographical restrictions to avoid ensonification of shipping noise.The emphasis for future research should be on obtaining more baseline information about the population distribution,sound production,hearing capabilities at the population level,behavior,and stress hormones of the humpback dolphins under different noise conditions or under different noise-producing activities,and/or in high-noise areas compared with relatively quiet areas,and the noise characteristics of ships of different types,sizes and speeds.

Temporal variation of the underwater soundscape in Jiaotou Bay,an Indo-Pacific humpback dolphin(Sousa chinensis)habitat off Hainan Island,China

The underwater soundscape is an important ecological element affecting numerous aquatic animals,in particular dolphins,which must identify salient cues from ambient ocean noise.In this study,temporal variations in the soundscape of Jiaotou Bay were monitored from February 2016 to January 2017,where a population of Indo-Pacific humpback dolphins(Sousa chinensis)has recently been a regular sighting.An autonomous acoustic recorder was deployed in shallow waters,and 1/3-octave band sound pressure levels(SPLs)were calculated with central frequencies ranging from 25 Hz to 40 kHz,then were grouped into 3 subdivided bands via cluster analysis.SPLs at each major band showed significant differences on a diel,fishing-related period,seasonal,and tidal phase scale.Anthropogenic noise generated by passing ships and underwater explosions were recorded in the study area.The fish and dolphin acoustic activities both exhibited diel and seasonal variations,but no tidal cycle patterns.A negative significant relationship between anthropogenic sound detection rates and dolphin detection rates were observed,and fish detection rates showed no effect on dolphin detection rates,indicating anthropogenic activity avoidance and no forced foraging in dolphins in the study area.The results provide fundamental insight into the acoustic dynamics of an important Indo-Pacific humpback dolphin habitat within a coastal area affected by a rapid increase in human activity,and demonstrate the need to protect animal habitat from anthropogenic noises.

Effects of residual stenosis on carotid artery after stent implantation: A numerical study

Stent deployments with residual stenosis(RS)were linked to increased risk of in-stent restenosis and thrombosis.The objective of the present work was to explore the underlying biomechanical mechanism(s)for adverse events with RS.The patient-specific carotid models with RS were constructed to investigate wall shear stress(WSS),velocity,relative residence time(RRT),and oscillating shear index(OSI)after stenting in the host artery.The results showed that stented artery accompanied by RS would result in evident vortex,stagnation and recirculation zone at the stenosis throat,where relatively more areas were at abnormal low level of TAWSS,high level of RRT and OSI.Moreover,effects of stenting with RS on velocity,WSS,RRT and OSI in host artery would be significantly enhanced by severe RS,long stent and common carotid artery(CCA)stenting.These results indicated that stenting with RS might aggravate adverse flow around the stent and the other region without stent,leading to increased adverse events in clinic.Therefore,to obtain better poststenting outcomes,stenting with RS requires caution and careful consideration,especially for the host artery with a severe RS,long stent and some locations of stenting.