[Discussion and Concern on Animal Study for Orthopaedic Implantable Devices].

In recent years, new orthopaedic implantable devices continue to emerge, which require higher requirements for technical evaluation. Animal study is an important part of the research and development process for the new orthopedic implantable devices, which provides relevant evidence for product design and stereotyping. By introducing the purpose of animal study, and the application of 3R principle (replacement, reduction, refinement) in this field, we summarize the concern on the animal study, in order to provide reference for the development and research of new orthopedic implantable devices and biomaterials. At the same time, the application of evidence-based research methods such as systematic review in the field is introduced, which provides new tools and approaches for the technical review and regulatory science.

[Discussion of Application Status and Key Attentions on Registration for Ossicular Replacement Prosthesis].

The ossicular replacement prosthesis should have good biocompatibility, stability, easy to install, and excellent sound transmission capacity. In this study, the characteristics of ideal materials for the ossicular replacement prosthesis were analyzed by searching the types of materials used in clinical practice and comparing the advantages and disadvantages of various materials and structures. At the same time, in combination with the current evaluation requirements and evaluation experience, the focus of the performance research project of ossicular replacement prosthesis in the process of registration is discussed to clarify the performance evaluation requirements of these products, so as to provide reference for the future work of manufacturers and regulators. The performance evaluation of ossicular replacement prosthesis focuses on its mechanical properties, fixation stability, sound transmission characteristics, biological characteristics, and magnetic resonance compatibility.

[Discussion on Key Attention in Technical Review for Additive Manufacturing Acetabular Reconstruction Implantable Device].

With the development of additive manufacturing, the advantages of this type implant devices in the treatment of acetabular defects and reconstruction are becoming more and more prominent. The number of registration and declaration of such products is increasing day by day. According to the relevant requirements of the National Medical Products Administration for registration and application documents, combined with the characteristics of acetabular reconstruction implant products made of additive manufacturing, this study analyzes and summarizes the relevant requirements on raw material control, product performance research, product manufacturing, clinical evaluation, et al. We should pay more attention to in the registration and application materials submitted by the applicant. Provide opinions and suggestions for the next registration applicant to standardize product R&D and registration application documents, in order to help them optimize product R&D process, improve product quality and registration application efficiency.

[Analysis of Key Points and Difficulties in Registration Application of Inflatable Bone Expander].

With the advantages of inflatable bone expander in the treatment of osteoporotic vertebral compression fractures, the number of applications for registration of such products is increasing. Based on the characteristics of the medical device, this article analyzed and summarized the relevant requirements for the basic information, product performance research, product manufacturing, clinical evaluation, and product instructions that should be focused on the registration application dossiers, as well as comply with the requirements of CMDE. The focus of the registration application for Inflatable Bone Expander should be the standardization of the application dossiers, while the difficulty was the scientific rationality of the research data. Comments and suggestions are provided to relevant practitioners on standardization of registration application dossiers. It may help them to optimize the quality of registration application dossiers while improve the efficiency of registration applications.

Adaptive strategies of high-flying migratory hoverflies in response to wind currents.

Large migrating insects, flying at high altitude, often exhibit complex behaviour. They frequently elect to fly on winds with directions quite different from the prevailing direction, and they show a degree of common orientation, both of which facilitate transport in seasonally beneficial directions. Much less is known about the migration behaviour of smaller (10-70 mg) insects. To address this issue, we used radar to examine the high-altitude flight of hoverflies (Diptera: Syrphidae), a group of day-active, medium-sized insects commonly migrating over the UK. We found that autumn migrants, which must move south, did indeed show migration timings and orientation responses that would take them in this direction, despite the unfavourability of the prevailing winds. Evidently, these hoverfly migrants must have a compass (probably a time-compensated solar mechanism), and a means of sensing the wind direction (which may be determined with sufficient accuracy at ground level, before take-off). By contrast, hoverflies arriving in the UK in spring showed weaker orientation tendencies, and did not correct for wind drift away from their seasonally adaptive direction (northwards). However, the spring migrants necessarily come from the south (on warm southerly winds), so we surmise that complex orientation behaviour may not be so crucial for the spring movements.

Multiscale analyses on a massive immigration process of Sogatella furcifera (Horváth) in south-central China: influences of synoptic-scale meteorological conditions and topography.

Mass landings of migrating white-backed planthopper, Sogatella furcifera (Horváth), can lead to severe outbreaks that cause heavy losses for rice production in East Asia. South-central China is the main infestation area on the annual migration loop of S. furcifera between the northern Indo-China Peninsula and mainland China; however, rice planthopper species are not able to survive in this region over winter. In this study, a trajectory analysis of movements from population source areas and a spatiotemporal dynamic analysis of mesoscale and synoptic weather conditions from 7 to 10 May 2012 were conducted using the weather research and forecasting (WRF) model to identify source areas of immigrants and determine how weather and topographic terrain influence insect landing. A sensitivity experiment was conducted with reduced topography using the WRF model to explain the associations among rainfall, topography, and light-trap catches of S. furcifera. The trajectory modeling results suggest that the source areas of S. furcifera immigrants into south-central China from 8 to 10 May were mainly southern Guangxi, northern Vietnam, and north-central Vietnam. The appearance of enormous catches of immigrant S. furcifera coincided with a period of rainstorms. The formation of transporting southerly winds was strongly associated with the topographic terrain. Additionally, the rainfall distribution and intensity over south-central China significantly decreased when topography was reduced in the model and were directly affected by wind circulation, which was associated with mountainous terrain that caused strong convection. This study indicates that migrating populations of S. furcifera were carried by the southwesterly low-level jets and that topographically induced convergent winds, precipitation, low temperatures, and wind shear acted as key factors that led to massive landings.

[Discussion on Clinical Trial Design of Artificial Hip Prosthesis].

Recently, the registration of artificial hip prosthesis products increased year by year. In the new version of the provisions for medical device registration, the domestic or import of such products in the registration declaration may need to complete a clinical trial in the country. How to carry out scientific clinical trials of the product design is the common concern of enterprises and clinical trial institutions. To review the guideline and literature concerning registration for artificial hip prosthesis, the focus on clinical trial design of artificial hip prosthesis include clinical inclusion, evaluation standard, sample size. Through the discussion, we hope to provide advice and guidance for clinical trials of this kind of products.

Geographic Variation of Diapause and Sensitive Stages of Photoperiodic Response in Laodelphax striatellus Fallén (Hemiptera: Delphacidae).

Large numbers of the small brown planthopper Laodelphax striatellus (Fallén) (Hemiptera: Delphacidae) occur in temperate regions, causing severe losses in rice, wheat, and other economically important crops. The planthoppers enter diapause in the third- or fourth-instar nymph stage, induced by short photoperiods and low temperatures. To investigate the geographic variation in L. striatellus diapause, we compared the incidence of nymphal diapause under various constant temperature (20 and 27 °C) and a photoperiod of 4:20, 8:16, 10:14, 12:12, 14:10, and 16:8 (L:D) h regimes among three populations collected from Hanoi (21.02° N, 105.85° E, northern Vietnam), Jiangyan (32.51° N, 120.15° E, eastern China), and Changchun (43.89° N, 125.32° E, north-eastern China). Our results indicated that there were significant geographic variations in the diapause of L. striatellus. When the original latitude of the populations increased, higher diapause incidence and longer critical photoperiod (CP) were exhibited. The CPs of the Jiangyan and Changchun populations were ∼ 12 hr 30 min and 13 hr at 20 °C, and 11 hr and 11 hr 20 min at 27 °C, respectively. The second- and third-instar nymphs were at the stage most sensitive to the photoperiod. However, when the fourth- and fifth-instar nymphs were transferred to a long photoperiod, the diapause-inducing effect of the short photoperiod on young instars was almost reversed. The considerable geographic variations in the nymphal diapause of L. striatellus reflect their adaptation in response to a variable environment and provide insights to develop effective pest management strategies.

Bluish-green afterglow and blue photoluminescence of undoped BaAl2O4.

Undoped BaAl2O4 was derived via sol-gel combustion technique. The afterglow and photoluminescence (PL) properties of undoped BaAl2O4 were explored with the combination of experiments and density functional theory (DFT) calculations. Undoped BaAl2O4 is found to display bluish-green afterglow that is discernible to naked eye in dark for about 20 s. The broad afterglow spectrum of undoped BaAl2O4 is peaked at around 495 nm. As a contrast, the broad PL spectrum of undoped BaAl2O4 can be decomposed into a bluish-green PL band peaking at about 2.53 eV (490 nm) and a blue PL band centered at about 3.08 eV (402.6 nm). DFT calculations indicate that the defect energy levels generated by oxygen and barium vacancies are critical to the afterglow and PL of undoped BaAl2O4. This work demonstrates that the oxygen and barium vacancies in undoped BaAl2O4 are liable for the bluish-green afterglow and blue PL of undoped BaAl2O4. The recorded bluish-green afterglow of BaAl2O4 is particularly important to understand the afterglow mechanisms of rare-earth doped BaAl2O4.

Plain metallic biomaterials: opportunities and challenges.

The 'plainification of materials' has been conceptualized to promote the sustainable development of materials. This perspective, for the first time in the field of biomaterials, proposes and defines 'plain metallic biomaterials (PMBs)' with demonstrated research and application case studies of pure titanium with high strength and toughness, and biodegradable, fine-grained and high-purity magnesium. Then, after discussing the features, benefits and opportunities of PMBs, the challenges are analyzed from both technical and regulatory aspects. Regulatory perspectives on PMB-based medical devices are also provided for the benefit of future research, development and commercialization.

Water-soluble o-hydroxycinnamate as an efficient photoremovable protecting group of alcohols with fluorescence reporting.

Two new o-hydroxycinnamates have been prepared for photoremovable protecting groups, and their photochemistry has been investigated. The photolysis of two caged compounds can efficiently release the corresponding alcohol in aqueous solutions, and the uncaging reaction proceeds with large one-photon excitation cross sections (1919 and 1535 M(-1) cm(-1)). The uncaging process has been observed by NMR spectroscopy. The caged compounds exhibit good aqueous solubility and excellent resistance to hydrolysis in a buffer solution.

Diffusing Mn4+ into Dy3+ Doped SrAl2O4 for Full-Color Tunable Emissions.

Dy3+ and Mn4+ codoped SrAl2O4 (SrAl2O4:Dy3+,Mn4+) phosphors were obtained by diffusing Mn4+ ions into Dy3+-doped SrAl2O4 via the constant-source diffusion technique. The influences of diffusion temperature and diffusion time on the emissions of SrAl2O4:Dy3+,Mn4+ were investigated. It was found that: (i) efficient red emission peaking at 651 nm can be readily achieved for SrAl2O4:Dy3+ by simply diffusing Mn4+ into SrAl2O4:Dy3+ at 800 °C and above; (ii) the red emission of Mn4+ becomes dominant over the characteristic emissions of Dy3+ when the diffusion temperature is 900 °C or higher; and (iii) the intensity of the red emission of SrAl2O4:Dy3+,Mn4+ is far more sensitive to diffusion temperature than to diffusion time. Our results have demonstrated that full-color tunable emissions can be realized for SrAl2O4:Dy3+, Mn4+ by tuning the parameters of diffusion temperature and diffusion time, which opens up a space for realizing easy color control of Dy3+-doped inorganic materials.

Photoluminescence and afterglow of Dy3+ doped CaAl2O4 derived via sol-gel combustion.

With doping concentration varying from 0.1 to 5.0 mol%, a series of Dy3+ doped calcium aluminate (CaAl2O4:Dy3+) phosphors were synthesized via a sol-gel combustion technique. The phase, morphology, photoluminescence (PL), afterglow, and thermoluminescence (TL) glow curves of CaAl2O4:Dy3+ were investigated by means of X-ray diffractometry, scanning electron microscopy, transmission electron microscopy, PL spectroscopy, afterglow spectroscopy, and TL dosimetry, respectively. It is found that: (i) oxygen vacancies and Dy3+ work as two independent sets of luminescence centers of PL for CaAl2O4:Dy3+; (ii) Dy3+ works as the luminescence center of afterglow for CaAl2O4:Dy3+; (iii) the afterglow of CaAl2O4:Dy3+ lasts for about 115 min at the optimal doping concentration of around 0.8 mol%; and (iv) multiple traps, which are sensitive to doping concentration, are present in CaAl2O4:Dy3+. The PL and afterglow mechanisms of CaAl2O4:Dy3+ are discussed to reveal the processes of charged carrier excitation, migration, trapping, detrapping, and radiative recombination in CaAl2O4:Dy3+.

Male nutritional status does not impact the reproductive potential of female Cnaphalocrocis medinalis moths under conditions of nutrient shortage.

In addition to sperm, some accessory substances transferred to females during copulation act as nuptial gifts by passing on valuable nutrients in many insect species. The nutritional status of the males can thus have a great effect on the mating behavior, fecundity and even the longevity of females. However, little is known about the effect of male nutritional status on the female reproductive traits in migratory insect species, particularly when females experience nutrient shortage and have to choose between reproduction and migration. Here, Cnaphalocrocis medinalis, a migratory rice pest in Asia, was studied to explore this issue. Our results showed that in male moths fed with honey solution, their gonads had higher energy content than gonads of starved males, resulting in increased energy content of the bursa copulatrix of females after mating with fed males. Such females showed increased mating frequency, fecundity and longevity compared to females mating with starved males, indicating that male moths deliver nuptial gifts to females and improve their reproductive performance. However, when females were starved, only about 45% mated, with just a single copulation, regardless of male nutritional status. Starved females showed lower fecundity, and a longer pre-oviposition period (indicating a greater propensity to migrate), compared to fed females. However, copulation still significantly extended their longevity. These results suggest that starved females invest in migration to escape deteriorating habitats, rather than investing the nuptial gift to increased fecundity. Our results further our understanding of the reproductive adaptability of migratory insects under conditions of food stress.

Immigration Pathways of White-Backed Planthopper in the Confluence Area of the Two Monsoon Systems.

The white-backed planthopper, WBPH, Sogatella furcifera (Horváth) is a plant pest that migrates long-distances. The migration pathway of WBPH in eastern China coincides with the north-south round trip of the East Asian monsoon. However, in Yunnan China, which is affected by two monsoon systems, the migration pathway is unclear. Light-trap data and analysis of female ovarian development showed that the peak period of immigration of WBPH into western Yunnan was earlier than in eastern Yunnan. Using meteorological reanalysis data and flight parameters of WBPH, trajectory modeling showed that there are two immigration pathways to Yunnan. One is from Myanmar to western Yunnan, and the other is from Vietnam and Laos to eastern Yunnan. The reason for the differences in source areas and immigration pathways between eastern and western Yunnan is that the west wind prevails in western Yunnan and is controlled by South Asian monsoon, while southwesterly winds prevail in eastern Yunnan due to the combined influence of South Asian monsoon and East Asian monsoon. The results indicate that WBPH invades Yunnan via two pathways under a two-monsoon system. These data will allow earlier prediction and population management of WBPH.

Detection and phylogenetic analysis of Wolbachia in the Asiatic rice leafroller, Cnaphalocrocis medinalis, in Chinese populations.

Wolbachia are a group of intracellular inherited endosymbiontic bacteria infecting a wide range of insects. In this study the infection status of Wolbachia (Rickettsiales: Rickettsiaceae) was measured in the Asiatic rice leafroller, Cnaphalocrocis medinalis (Guenée) (Lepidoptera: Pyralidae), from twenty locations in China by sequencing wsp, ftsZ and 16S rDNA genes. The results showed high infection rates of Wolbachia in C. medinalis populations. Wolbachia was detected in all geographically separate populations; the average infection rate was ~ 62.5%, and the highest rates were 90% in Wenzhou and Yangzhou populations. The Wolbachia detected in different C. medinalis populations were 100% identical to each other when wsp, ftsZ, and 16S rDNA sequences were compared, with all sequences belonging to the Wolbachia B supergroup. Based on wsp, ftsZ and 16S rDNA sequences of Wolbachia, three phylogenetic trees of similar pattern emerged. This analysis indicated the possibility of inter-species and intra-species horizontal transmission of Wolbachia in different arthropods in related geographical regions. The migration route of C. medinalis in mainland China was also discussed since large differentiation had been found between the wsp sequences of Chinese and Thai populations.

Green Afterglow of Undoped SrAl2O4.

Undoped SrAl2O4 nanocrystals were obtained via solution combustion using urea as fuel. The afterglow properties of undoped SrAl2O4 were investigated. Green afterglow from undoped SrAl2O4 is visible to the human eye when the 325 nm irradiation of a helium-cadmium laser (13 mW) is ceased. The afterglow spectrum of undoped SrAl2O4 is peaked at about 520 nm. From the peak temperature (321 K) of the broad thermoluminescence glow curve, the trap depth of trap levels in undoped SrAl2O4 is estimated to be 0.642 eV using Urbach's formula. Based on first-principles density functional calculations, the bandstructures and densities of states are derived for oxygen-deficient SrAl2O4 and strontium-deficient SrAl2O4, respectively. Our results demonstrate that the green afterglow of undoped SrAl2O4 originates from the midgap states introduced by oxygen and strontium vacancies. The observation of green afterglow from undoped SrAl2O4 helps in gaining new insight in exploring the afterglow mechanisms of SrAl2O4-based afterglow materials.

Blue Photoluminescence and Cyan-Colored Afterglow of Undoped SrSO4 Nanoplates.

Undoped SrSO4 nanoplates were synthesized via the composite hydroxide-mediated approach. The products were characterized by means of X-ray diffractometry, scanning electron microscopy, X-ray energy-dispersive spectroscopy, X-ray photoelectron spectroscopy, photoluminescence (PL) spectroscopy, electron spin resonance technique, afterglow spectroscopy, and thermoluminescence dosimetry. The steady-state PL spectrum of undoped SrSO4 nanoplates can be deconvoluted into two distinct Gaussian bands centered at 2.97 eV (417.2 nm) and 2.56 eV (484.4 nm), respectively. The nature of the defect emissions is confirmed through the emission-wavelength-dependent PL decays as well as the excitation-wavelength-dependent PL decays. A cyan-colored afterglow from undoped SrSO4 nanoplates can be observed with naked eyes in the dark, and the afterglow spectrum of the undoped SrSO4 nanoplates exhibits a peak at about 492 nm (2.52 eV). The duration of the afterglow is measured to be 16 s. The thermoluminescence glow curve of the undoped SrSO4 nanoplates shows a peak at about 40.1 °C. The trapping parameters are determined with the peak shape method, the calculated value of the trap depth is 0.918 eV, and the frequency factor is 1.2 × 1014 s-1. Using density functional calculations, the band structures and densities of states of oxygen-deficient SrSO4 and strontium-deficient SrSO4 are presented. The mechanisms of the cyan-colored afterglow are discussed for undoped SrSO4, and the oxygen vacancies in SrSO4 are proposed to be the luminescence center of the afterglow.

Biodegradable metals for bone defect repair: A systematic review and meta-analysis based on animal studies.

Biodegradable metals are promising candidates for bone defect repair. With an evidence-based approach, this study investigated and analyzed the performance and degradation properties of biodegradable metals in animal models for bone defect repair to explore their potential clinical translation. Animal studies on bone defect repair with biodegradable metals in comparison with other traditional biomaterials were reviewed. Data was carefully collected after identification of population, intervention, comparison, outcome, and study design (PICOS), and following the inclusion criteria of biodegradable metals in animal studies. 30 publications on pure Mg, Mg alloys, pure Zn and Zn alloys were finally included after extraction from a collected database of 2543 publications. A qualitative systematic review and a quantitative meta-analysis were performed. Given the heterogeneity in animal model, anatomical site and critical size defect (CSD), biodegradable metals exhibited mixed effects on bone defect repair and degradation in animal studies in comparison with traditional non-degradable metals, biodegradable polymers, bioceramics, and autogenous bone grafts. The results indicated that there were limitations in the experimental design of the included studies, and quality of the evidence presented by the studies was very low. To enhance clinical translation of biodegradable metals, evidence-based research with data validity is needed. Future studies should adopt standardized experimental protocols in investigating the effects of biodegradable metals on bone defect repair with animal models.

Plagues of Desert Locusts: Very Low Invasion Risk to China.

Recently, the most serious upsurge of the desert locust (Schistocerca gregaria) in the last 25 years is spreading across eastern Africa and southwestern Asia. Parts of the desert locust 'invasion area', namely the northern border areas of Pakistan and India, are very close to China, and whether locust swarms will invade China is of wide concern. To answer this question, we identified areas of potentially suitable habitat for the desert locust within China based on historical precipitation and temperature data, and found that parts of Xinjiang and Inner Mongolia provinces could provide ephemeral habitat in summer, but these places are remote from any other desert locust breeding areas. New generation adults of the desert locust in Pakistan and India present since April led to swarms spreading into the Indo-Pakistan border region in June, and so we examined historical wind data for this period. Our results showed that winds at the altitude of locust swarm flight blew eastward during April-June, but the wind speeds were quite slow and would not facilitate desert locust eastward migration over large distances. Simulated trajectories of desert locust swarms undertaking 10-day migrations mostly ended within India. The most easterly point of these trajectories just reached eastern India, and this is very close to the eastern border of the invasion area of desert locusts described in previous studies. Overall, the risk that the desert locust will invade China is very low.