Syntheses and Crystal Structures of Three Coordination Complexes Based on Ln(Ⅲ) and mpca-Ligand

Three complexes obtained by the reaction of Pr（Ⅲ） or Nd（Ⅲ） salts with 5-methyl-2-pyrazinecarboxylic acid（Hmpca） are structurally determined by single-crystal X-ray diffraction.Complex [Pr（mpca-）3（H2O）2]2·6H2O（1） is composed of dinuclear Pr（Ⅲ） units with two metal centers bridged by two anionic mpca-ligands in a κ^3O,O＇：O＇ bridging mode.Complexes [Pr（mpca-）3]n（2） and [Nd（mpca-）3]n（3） are isostructures,and they consist of polymeric chains based on Ln（Ⅲ） and mpca-ligands.Each pair of adjacent metal centers is linked by three mpca-molecules in a κ^3N,O：O bridging mode.

Ferroptosis inhibition protects vascular endothelial cells and maintains integrity of the blood-spinal cord barrier after spinal cord injury

Maintaining the integrity of the blood-spinal cord barrier is critical for the recove ry of spinal cord injury.Ferro ptosis contributes to the pathogenesis of spinal cord injury.We hypothesized that ferroptosis is involved in disruption of the blood-s pinal cord barrier.In this study,we administe red the ferroptosis inhibitor liproxstatin-1 intraperitoneally after contusive spinal co rd injury in rats.Liproxstatin-1 improved locomotor recovery and somatosensory evoked potential electrophysiological performance after spinal cord inju ry.Liproxstatin-1 maintained blood-spinal cord barrier integrity by upregulation of the expression of tight junction protein.Liproxstatin-1 inhibited ferroptosis of endothelial cell after spinal cord injury,as shown by the immunofluorescence of an endothelial cell marker(rat endothelium cell antigen-1,RECA-1) and fe rroptosis markers Acyl-CoA synthetase long-chain family member 4 and 15-lipoxygenase.Liproxstatin-1reduced brain endothelial cell ferroptosis in vitro by upregulating glutathione peroxidase 4 and downregulating Acyl-CoA synthetase long-chain family member4 and 15-lipoxygenase.Furthermore,inflammatory cell recruitment and astrogliosis were mitigated after liproxstatin-1 treatment.In summary,liproxstatin-1im proved spinal cord injury recovery by inhibiting ferroptosis in endothelial cells and maintaining blood-s pinal co rd barrier integrity.

Viscoelasticity of repaired sciatic nerve by poly(lactic-co-glycolic acid) tubes

Medical-grade synthetic poly（lactic-co-glycolic acid） polymer can be used as a biomaterial for nerve repair because of its good biocompatibility, biodegradability and adjustable degradation rate. The stress relaxation and creep properties of peripheral nerve can be greatly improved by repair with poly（lactic-co-glycolic acid） tubes. ＂Fen sciatic nerve specimens were harvested from fresh corpses within 24 hours of death, and were prepared into sciatic nerve injury models by creating a 10 mm defect in each specimen. Defects were repaired by anastomosis with nerve autografts and poly（lactic-co-glycolic acid） tubes. Stress relaxation and creep testing showed that at 7 200 seconds the sciatic nerve anastomosed by poly（lactic-co-glycolic acid） tubes exhibited a greater decrease in stress and increase in strain than those anastomosed by nerve autografts. These findings suggest that poly（lactic-co-glycolic acid） exhibits good viscoelasticity to meet the biomechanical require- ments for a biomaterial used to repair sciatic nerve injury.

Automated spectral classification using template matching

An automated spectral classification technique for large sky surveys is proposed. We firstly perform spectral line matching to determine redshift candidates for an observed spectrum, and then estimate the spectral class by measuring the similarity between the observed spectrum and the shifted templates for each redshift candidate. As a byproduct of this approach, the spectral redshift can also be obtained with high accuracy. Compared with some approaches based on computerized learning methods in the literature, the proposed approach needs no training, which is time-consuming and sensitive to selection of the training set. Both simulated data and observed spectra are used to test the approach; the results show that the proposed method is efficient, and it can achieve a correct classification rate as high as 92.9%, 97.9% and 98.8% for stars, galaxies and quasars, respectively.

Failure analysis of air fan blades

The failure of all 12 blades of an air fan was investigated by metallurgical and mechanical experiments and an examina-tion of the fracture surface. The experimental results show that the cast aluminium-silicon alloy without any modification had a number of material defects, such as coarse grains, a loose structure, a large number of shrinkage holes, a long and thin bold-pin shaped silicon-phase, poor material strength and serious brittleness. In addition, installed on the spindle without elastic conjunction, blade No.10 vibrated and inevitably.spun off due to the large centrifugal force. Therefore, blade No.10 first cracked at the locking handle, then broke at the root, which caused all the other 11 blades to be broken by the crack of blade No.10.

A Simple Construction of Gabor Frames for L^2（R）

In this paper, we give a method which aUows us to construct a class of Parseval frames for L2（R） from Fourier frame for L2（X）. The result shows that the function which generates a Oabor frame by translations and modulations has ＂good＂ properties, i.e., it is suifficiently smooth and compactly supported.

Tribological Behavior of Benzothiazoline Derivative as Additive in Rapeseed Oil

A novel lubricating oil additive 3-((2-(2-hydroxyethyl)-1,3,2,6-dioxazaborocan-6-yloxy)methyl) benzo[d] thiazole-2(3H)-thione(BTD) was synthesized.The product was characterized by FTIR,elemental analysis,and thermogravimetric analysis(TGA).Four-ball tribological tests showed that the addition of a definite concentration of this additive to rapeseed oil could effectively increase both the load-carrying capacity,resistance to wear,and friction-reducing abilities of the oil.Scanning electron microscopy(SEM) observations have confirmed that the additive could result in a reduced diameter of the wear scar.

Autologous exosome facilitates load and target delivery of bioactive peptides to repair spinal cord injury

Spinal cord injury(SCI)causes motor,sensory and automatic impairment due to rarely axon regeneration.Developing effective treatment for SCI in the clinic is extremely challenging because of the restrictive axonal regenerative ability and disconnection of neural elements after injury,as well as the limited systemic drug delivery efficiency caused by blood spinal cord barrier.To develop an effective non-invasive treatment strategy for SCI in clinic,we generated an autologous plasma exosome(AP-EXO)based biological scaffold where AP-EXO was loaded with neuron targeting peptide(RVG)and growth-facilitating peptides(ILP and ISP).This scaffold can be targeted delivered to neurons in the injured area and elicit robust axon regrowth across the lesion core to the levels over 30-fold greater than naïve treatment,thus reestablish the intraspinal circuits and promote motor functional recovery after spinal cord injury in mice.More importantly,in ex vivo,human plasma exosomes(HP-EXO)loaded with combinatory peptides of RVG,ILP and ISP showed safety and no liver and kidney toxicity in the application to nude SCI mice.Combining the efficacy and safety,the AP-EXO-based personalized treatment confers functional recovery after SCI and showed immense promising in biomedical applications in treating SCI.It is helpful to expand the application of combinatory peptides and human plasma derived autologous exosomes in promoting regeneration and recovery upon SCI treatment.

Issues in conserving'orphan heritage'in Asia:WWIl battlefield conservation in Hong Kong and Malaysia

Wars and conflict have existed since the beginning of time.Most battlefield conservation work is done for battlefields that lie in the borders of the nations that were involved,thus fostering citizens'personal ties with the site and their national identities.However,some areas of the world suffer from conservation neglect because of the distance and separation between the battlefield's location and the country to which it is relevant,thus creating a dislocated appreciation of heritage described by Price(Confl Archaeol 1:181-196,2005)as'orphan heritage'.This paper questions the extent to which post-colonial nations are willing to protect and conserve World WarⅡbattlefields on their soil.It examines two battlefields in Asia-the Gin Drinkers'Line in Hong Kong,China,and the Green Ridge battlefield in Kampar,Malaysia--that have been the subject of campaigns to recognise their transnational heritage value.Both battles involved multinational Allied forces led by the British against Japanese troops.A combination of political and economic factors has influenced how the two battlefields are understood and appreciated by citizens and local governments in the host nations.The paper delineates how these two Asian battlegrounds,which are relatively unknown to the general public,have been brought to the public's attention and by whom as well as how the local governments have handled the demand to safeguard the battlefields.We argue that the global nature of WWⅡmakes its commemoration geographically challenging and politically contentious.The WWⅡbattlefields in Asia attest to the historical authenticity of past conflicts and thus should be conserved as neutrally as possible.The successful protection of battlefields in Malaysia and Hong Kong thus far can be largely attributed to grassroots initiatives,pressure from stakeholder countries,such as the UK,and academic research whereby the significance of the battleground is made known to people in Hong Kong and Malaysia.With public support,responsible government leadership and a shared understanding of their importance as transnational heritage,WWⅡbattlefields can help calm bitter resentment and promote reconciliation.

Perceptions of Malaysian medical students from different academic years on primary care:a qualitative research

Objective To explore the perception of medical students from a private medical college in Perak,Malaysia,on primary care practice and induce the factors influencing their perception and willingness to consider primary care as a career pathway.Design Qualitative study using focus group discussions.Participants’responses were audio recorded,transcribed,grouped under various domains and listed out and analysed.Setting A private medical college in Perak state,Malaysia.Participants Forty-six medical students from years 2 to 5 were included.Eight focus groups were formed with two focus groups from each academic year(six students each in seven groups and four students in one group).Students were informed through their respective student leader of each year and received a participant information sheet and an informed consent form which were completed and returned if they decided to participate in the focus group discussions.results The participants had different levels of understanding of primary care depending on their level of exposure to primary care.Senior students with more exposure had a better understanding about primary care and its services.Attractive factors towards choosing primary care as a career included short working hours with a more balanced family and social life,being able to treat patients as a whole with continuity of care and closer relationship with patients.Unattractive factors included routine,unchallenging and boring practice,poor salary,work overload and administrative work in government clinics,being less recognised by other specialties;and the poor perception by other doctors that those pursuing primary care were not‘brilliant enough’for more‘sophisticated disciplines like surgery or paediatrics’.Conclusion This study showed that the medical students’level of exposure to primary care played a crucial role in determining their understanding of primary care practice and their choice of career in primary care.Issues to be addressed include remuneration,workload and the prejudice against primary care as a career pathway.Suggestions included introducing early exposure to fun and challenging primary care postings in the medical curriculum and producing well trained,skilled and enthusiastic role models.