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Laser powder bed fusion (LPBF) fabricated Al–Mn–Mg-Sc-Zr alloy generally possesses a bi-modal microstructure of columnar grains and equiaxed grains. Such an anisotropic microstructure would introduce varied tensile performance in different orientations. To date, few study on the microstructure and tensile property anisotropy have been reported for LPBF fabricated Al–Mn–Mg-Sc-Zr alloys built at different layer thicknesses, which limits the exploration in mechanical property optimization. In this work, the microstructure anisotropy and room-temperature tensile properties of LPBF produced and peak-aged Al–Mn–Mg-Sc-Zr alloys built at 30 and 60 μm layer thicknesses were systematically investigated by scanning electron microscope, transmission electron microscope, and tensile testing. A higher layer thickness of 60 μm resulted in coarser grains with the precipitates size remained similarly compared to the 30 μm specimens. This led to a reduced yield strength in 60 μm specimens (492–509 MPa) comparing to those in 30 μm specimens at 502 MPa–510 MPa. In addition, the existence of columnar grains within melt pools contributed to a larger effective slip length in the vertical direction than that in the horizontal orientation. Such difference in effective slip length in the loading direction contributed to a lower strength in vertical orientations. For ductility, the slightly higher defect level in 60 μm specimens (0.58%) resulted in reduced elongations of 3%–6% compared to those of 30 μm specimens (0.10%). The ductility anisotropy was attributed to the preferential distribution of gas pores and keyhole defects at melt pool boundaries.

The recently emerged Al–Mn–Mg–Sc–Zr alloys were regarded as high-strength Al alloys suitable for high-temperature applications. However, the influence of laser powder bed fusion (LPBF) fabricated anisotropic microstructure on tensile creep performance has not been explored. In this work, we reported an anisotropic tensile creep behavior, which is superior in the vertical specimens than the horizontal counterparts. The tensile creep anisotropy was attributed to the bi-modal microstructure of columnar grains within melt pool and equiaxed grains at melt pool boundary, the “fish-scale” melt pool morphology and the resulted tortuous crack path in the vertical orientation.

With the escalating challenges of climate change and the imperative for carbon neutrality, evaluating the carbon footprint of regional power systems becomes crucial. To address this issue, a low-carbon evaluation framework for regional power systems is developed. First, this study identifies the fundamental requirements that the index system for the low-carbon power system should follow and specifies the general direction for the index system’s creation. Second, an evaluation model for carbon reduction ability is proposed by considering generation side, grid side and load side of the power system. Then, a comparative evaluation model for the carbon reduction capability of multi-regional power systems is proposed to spatiotemporally compare the carbon reduction capability of different power systems. Next, a quantification method for the weights of low-carbon evaluation indicators is established based on the power system simulation of multi-scenario scheduling and index sensitivity analysis method. Finally, a low-carbon comprehensive score for regional power systems is created by combining the evaluation results of the system’s carbon reduction capacity with index weights. The practical research results in a region of Zhejiang province in China demonstrate that the proposed model can provide a reasonable and feasible evaluation plan for the low-carbon construction of regional power systems.

Abstract The process of staining was frequently employed to enhance or alter the color of agate beads in ancient times. One of the key challenges in studying ancient beads is comprehending the intricate techniques employed to color agate stones. An understanding of the staining mechanism from a mineralogical standpoint offers insights into the level of technological advancement in different civilizations. In this study, the mineral structure of eight ancient agate beads from Xinjiang Uygur Autonomous Region, NW China, was analyzed using Micro X-ray fluorescence (µXRF), Raman spectroscopy, Scanning Electron Microscope (SEM), and Fourier Transform Infrared (FTIR) techniques. The color, transparency, mineral phase, and surface roughness of the beads were examined, revealing variations ranging from colorless to light violet to dark violet. Raman and FTIR spectroscopy were employed to determine the SiO2 phase and the changes in optical characteristics of agate beads after artificial staining. The black color of the beads was formed by carbon penetration, while the red color was produced by heating. The coexistence of α-quartz and moganite phases in the red, the dark red, the black, the idiochromatic white and the part translucent zones of the ancient beads was confirmed by the 464 cm−1 peak of α-quartz and the 502 cm−1 peak of moganite phase. The analyzed red, the dark red, the black, the idiochromatic white and the part translucent zones exhibited remarkably similar FTIR spectral features, with two prominent bands at ~ 1097 and ~ 1187 cm−1, as well as two weak bands at 798 and 778 cm−1, indicating the presence of moganite and α-quartz in the unetched ancient beads. In contrast to the idiochromatic white appearance of natural agate, the scattered white coloration in etched beads was generated by an etching reaction. Both Raman and FTIR spectroscopy indicated the absence of moganite in etched beads, indicating that the scattered white color was produced by the loss of moganite and a portion of α-quartz, resulting in a rough surface.

The high cost of laser powder bed fusion (LPBF) fabricated high-strength Sc containing aluminium alloy hinders its applications. To reduce the cost, we reported a LPBF fabricated strong and ductile Al–Mn–Mg–Sc–Zr alloy using large layer thicknesses to improve the fabrication efficiency on coarse powder particles. A high relative density exceeding 99.2% was achieved at layer thicknesses up to 120 μm. In post-process heat-treated specimens, the yield strength only had a slight 6% decrease from layer thickness of 30 to 120 μm; such a decrease in strength was attributed to the larger grain size resulted from the adopted larger layer thickness. The fabricated sample at layer thickness of 120 μm still exhibited high tensile yield strength of 472 MPa and fracture strain of ∼10%. This work showed a successful application of improving the LPBF fabrication efficiency of high-strength Al–Mn–Mg–Sc–Zr alloy using large layer thickness in LPBF process.

ABSTRACTBackground: The termination of pregnancy in patients with placenta accreta spectrum disorder (PASD) during the second trimester remains uncertain. In addition, interventional radiology techniques, such as arterial embolization and balloon placement, are potential options. We evaluated the outcomes of pregnancy termination in patients with PASD during the second trimester and the effectiveness of preoperative interventional radiology techniques.Methods: This retrospective study analyzed 48 PASD patients who underwent pregnancy termination during the second trimester between January 2016 and May 2021.Results: Of the 48 patients, 20 (41.67%) underwent transvaginal termination, whereas 28 (58.33%) underwent cesarean section. Notably, no significant differences were observed in success rates between the transvaginal termination and cesarean section groups (80.00% vs. 92.86%, P = 0.38). Furthermore, no statistically significant differences were observed in the success rates (94.12% vs 90.32%, P = 1.00) and blood loss (512.35 ± 727.00 ml vs 804.00 ± 838.98 ml, P = 0.23) between the artery embolization and non-embolization groups. In the vaginal termination group, statistically significant differences were observed in gestational weeks (16.70 ± 3.12 vs 22.67 ± 3.63, P

This paper deals with the problem of bipartite consensus for Takagi-Sugeno fuzzy multiagent systems on multilayer cooperation-competition networks and its application to image communication. Fuzzy control laws are proposed by using relative output measurements between neighboring agents, where additive couplings are considered to show the different layered-interactions. Sufficient conditions for bipartite consensus of the multilayer networks with signed graphs are obtained by using the signed graph theory, Lyapunov stability theory and Takagi-Sugeno fuzzy systems theory. Then, coupled chaotic Lorenz systems over multilayer signed-networks are illustrated to show the effectiveness of the obtained results. Finally, a new multiagent image communication system is constructed based on the bipartite consensus of the fuzzy multilayer coopetition multiagent network, in which two agents in different layers for point-to-point communication use the output measurements from their own and neighboring agents as the synchronous encryption/decryption keystreams. The experimental results show that the proposed multiagent image communication system has excellent performance against some classical attacks.

This paper is concerned with the problem of bipartite containment control design for a class of nonlinear multiagent systems with time-delays in agents’ states under impulsive false-data-injection attacks. The considered multiagent system is subject to Markovian variation in the signed communication topology. The graph among the followers is assumed to be structurally balanced for each Markovian switching mode. A memory distributed control protocol is proposed to achieve bipartite containment within the convex hull of leader agents as well as the symmetric convex hull. The bipartite containment control problem is solved by means of a Markovian switching Lyapunov function and the Razumikhin technique. In addition, the problem of bipartite leader-following consensus is also addressed for delayed nonlinear multiagent systems with one leader. Two examples are provided to show the effectiveness of the proposed control scheme, and comparison results with existing methods are given as well.

Platform heating is one of the effective strategies used in laser powder bed fusion (LPBF) to avoid cracking during manufacturing, especially when building relatively large-size components, as it removes significant process-induced residual strains. In this work, we propose a novel and simple method to spare the elaborate post-processing heat treatment typically needed for LPBF Al-Sc alloys without compromising the mechanical properties. We systematically investigated the effects of LPBF platform heating at 200 °C on the residual stress relief, microstructure, and mechanical performance of a high-strength Al-Mn-Sc alloy. The results reveal that LPBF platform heating at 200 °C is sufficient to largely relieve the process-induced residual stresses compared to parts built on an unheated 35 °C platform. Meanwhile, the platform heating triggered the dynamic precipitation of uniformly dispersed (1.5–2 nm) Sc-rich nano-clusters. Their formation in a high number density (1.75 × 1024 m−3) resulted in a ~20% improvement in tensile yield strength (522 MPa) compared to the build on the unheated platform, without sacrificing the ductility (up to 18%). The improved mechanical properties imply that platform heating at 200 °C can strengthen the LPBF-synthesised Sc-containing Al alloys via in situ aging, which is further justified by an in situ measurement study revealing that the developing temperatures in the LPBF part are within the aging temperature range of Al-Sc alloys. Without any post-LPBF treatments, these mechanical properties have proven better than those of most Al-Sc alloys through long-time post-LPBF heat treatment.

Abstract Under the background of carbon neutrality and large‐scale penetration of renewable energy, the integrated local energy system (ILES) has been extensively recognized as an effective way to reduce carbon emissions and improve renewable energy consumption level due to its high energy utilization and multiple energy complementarity. Hence, an optimal low‐carbon scheduling model of ILES considering oxygen‐enriched combustion plant (OECP) and generalized energy storages (GESs) is proposed in this paper to reduce the carbon emissions, improve the renewable energy consumption level and reduce the operating costs of ILES. More specifically, the cooperation mechanism between OECP and power to gas (P2G) is established to maintain a high carbon capture level during peak load periods; the GESs under the background of ILES is modelled, which can make full use of the multiple energy complementarity to improve the renewable energy consumption level of ILES. Case studies are performed on an IES that consists of an IEEE 33‐bus distribution network, a 44‐node district heating network and a 20‐node natural gas network to verify the effectiveness and advantages of the proposed model.

Objective: To compare the predictive value of different risk assessment methods for puerperium venous thromboembolism (VTE). Methods: This study included 55 women with and 165 women without puerperal VTE. Using the cases, 11 assessment methods were compared. Results: The area under the curve (AUC) value of the 11 assessments was highest for the modified Caprini risk assessment model for pregnancy (a modified risk scoring method from Caprini, AUC = 0.805). Pairwise comparison of the AUC values of the 11 assessment methods indicated no significant difference among the five methods with AUC values > 0.7. Among them, the modified Caprini, the risk scoring method recommended by the Swedish Guidelines (Swedish method), and the risk scoring method recommended by the Shanghai consensus (Shanghai method) performed better than the other six methods with AUC values

Numerical modelling is an effective tool to investigate the rapid temperature cycling in laser powder bed fusion. However, the high computational cost limits the modelling of part-scale components due to the significantly different scales between the highly local energy input region and the global field response region. This study presents a macroscale finite element thermal simulation strategy with a track-scale resolution by combining the recently developed characteristic time-based heat input (CTI) model with a currently proposed adaptive mesh re-mapping method. Due to the uniformly distributed power density along the scan direction in the CTI model, the optimized mesh strategy allows one element to capture the temperature solutions over the majority of a scan track except at the two ends. The adaptive mesh re-mapping method is used to map simulated results from a previous scan track model to a current scan track model with a new mesh configuration. This strategy has been implemented for a Ti-6Al-4V part with the dimensions of 20×40×3mm3. The predicted temperature histories agree well with the in-situ measurements at the points in both the printed part and powder bed. Three case studies demonstrate that our strategy can improve computational efficiency between 6 and 30 times.

Laser powder bed fusion (LPBF) is a timely important additive manufacturing technique that offers many opportunities for fabricating three-dimensional complex shaped components at a high resolution with short lead times. This technique has been extensively employed in manufacturing Ti-6Al-4V parts for aerospace and biomedical applications. However, many challenges, including poor surface quality, porosity, anisotropy in microstructure and property, and difficulty in tailoring microstructure, still exist. In this paper, we review the recent progress in post-process treatment and its influence on the microstructure evolution and material performance, including tensile, fatigue, fracture toughness, creep, and corrosion properties. The contradictions in simultaneously achieving high strength/ductility and strength/fracture toughness/creep resistance have been identified. Furthermore, research gaps in understanding the effects of the emerging bi-modal microstructure on fatigue properties and fracture toughness require further investigation.

Laser powder bed fusion (LPBF) is one of the major additive manufacturing techniques that industries have adopted to produce complex metal components. The scientific and industrial literature from the past few years reveals that there is a growing demand for the development of high-strength aluminium alloys for LPBF. However, some major challenges remain for high-strength aluminium alloys, especially in relation to printability and the control of defects. Possible strategies that have been identified to achieve high strength with printability include the adaptation of existing high-strength cast and wrought alloys to LPBF, the design of new alloys specifically for LPBF, and the development of aluminium-based composites to achieve unique combinations of properties and processability. Whilst review papers exist for aluminium alloys in general for the related work up to 2019, the purpose of this paper is to review the latest developments related to high-strength aluminium alloys for LPBF up to early 2022, including alloy and process design strategies to achieve high strength without cracking. It aims to provide fresh insights into the current state-of-the-art based on a review of extensive yield strength data for a wide spectrum of aluminium alloys and tempers that have been studied and/or commercialised for LPBF.

Abstract The primary goal of material management is to arrange the use of materials reasonably, which is particularly important for the construction industry. Wireless communication can transmit a lot of information in time in production, which can promote the management and arrangement of building materials. In order to explore the management method of prefabricated materials, this paper compares the prefabricated building materials management based on BIM with the traditional method and the management method combining BIM and wireless communication through sampling survey and sand table simulation. This paper compares the material procurement, storage and quality in the construction stage and analyzes the material management differences of different technical methods in different stages. The results show that the average inventory turnover rate of BIM-based management method is 6 times, and that of conventional method is 4 times. However, in the construction stage, the gap between the two methods is narrowed. The combination of wireless communication and BIM leads the whole process in inventory turnover rate. The turnover times of prefabricated building materials management method based on BIM Technology is reduced to 3 times, and that of conventional method is reduced to 2 times. However, the turnover times of BIM combined with wireless communication is more than 4 times. Therefore, BIM-based prefabricated building materials management can reduce the use of funds and the occupation of warehouse, and control the quality of materials better than the traditional methods. However, the combination of BIM and wireless communication can achieve better results.

In view of the high gas pressure and low permeability of deep coal seam, it is difficult to control gas, which affects the safety production of coal mine. The technical scheme of hydraulic fracturing to improve the permeability of coal seam is put forward, and the gas drainage technology is used to control the gas emission of coal seam. The fracturing effect under different water pressure, different gradient fracturing times, and in situ stress is analyzed by using 3DEC (3-Dimensional Distinct Element Code) discrete element software. The simulation analysis and field verification results show that the coal seam gas pressure increases linearly with the buried depth. In situ stress characteristics and hydraulic strength are the key factors affecting the effect of hydraulic fracturing. The fracturing radius increases with the increase of flow. When the construction pressure of hydraulic fracturing test is 18 MPa, the distance between fracturing hole and drainage hole is 8.5 m. The actual measurement shows that after hydraulic fracturing and gas drainage, the maximum gas emission is reduced by 51%, and the average gas emission is reduced by 58%.

Additive manufacturing (AM) of nickel superalloys typically leads to large columnar grains forming along the build direction, resulting in poor and anisotropic tensile performance. In this work, a novel AM process involving directed energy deposition (DED) combined with in-situ rolling was applied to fabricate a typical nickel superalloy – Inconel 718. The results revealed hierarchical layered refined grains formed in the microstructure, due to the unique dynamic and meta-dynamic recrystallization induced by the in-situ rolling during DED. Through this, an average grain size of ∼8 µm and much weaker texture was achieved for the in-situ rolled samples. Tensile test showed that a significant increase of over 50% in the yield strength was achieved for the in-situ rolled samples at both room temperature and 650°C, while maintaining a good uniform elongation above 10%.

Background: Adalimumab, golimumab, infliximab, certolizumab, and etanercept are five anti-tumor necrosis factor (anti-TNF) medicines that have been approved for use in rheumatology. Apart from their well-established therapeutic usefulness, -it is unclear to what extent -they are linked to an increased risk of various side effects. The present meta-analysis was carried out to assess the risk of infection and other side effects after anti-TNF- α for the treatment of rheumatoid arthritis, psoriatic arthritis, and ankylosing spondylitis.Methods: We searched PubMed, Cinahl (via Ebsco), Scopus, and Web of Sciences databases for trials comparing anti-TNF medications to placebo or no therapy in adult patients with rheumatoid arthritis, psoriatic arthritis, or ankylosing spondylitis from August 2006 to August 2020. A total of 23 articles were used for meta-analysis. The Cochrane Collaboration’s risk of bias tool was used to assess the methodological quality of the included studies. In addition, a random-effects model was used to calculate the pooled odds ratio, and Forest plots were constructed to determine the risk of infections and cancer following the use of anti-TNF treatment.Results: Treatment with anti-TNFα agents resulted in an increase in the risk of serious infections (OR: 1.72, 95% CI: 1.56–1.90, p < 0.00001) and an increase in cancer risk (OR: 1.36, 95% CI: 1.20–1.53, p < 0.00001) whereas the risk of developing tuberculosis was not significantly different with anti-TNFα agents versus those without treatment with anti-TNFα agents (OR: 2.55, 95% CI: 0.40–16.23, p = 0.32) although the number of studies is limited to make a definitive conclusion. The risk of bias of the included studies was unclear to high across most domains, and there was evidence of publication bias for most outcomes.Conclusion: The present meta-analysis suggests an increased risk of infectious adverse events, including overall adverse events and cancer following anti-TNFα treatment, whereas the risk of tuberculosis was not significantly different. Although anti-TNF agents have shown promise to treat inflammatory conditions, their use should be balanced by the risk-benefit ratio as suggested by the meta-analysis.

Objective: To evaluate the use of tourniquet and forceps to reduce bleeding during surgical treatment of severe placenta accreta spectrum (placenta increta and placenta percreta).Methods: A tourniquet was used in the lower part of the uterus during surgical treatment of severe placenta accreta spectrum. Severe placenta accreta spectrum was classified into two types according to the relative position of the placenta and tourniquet during surgery: upper-tourniquet type, in which the entire placenta was above the tourniquet, and lower-tourniquet type, in which part or all of the placenta was below the tourniquet. The surgical effects of the two types were retrospectively compared. We then added forceps to the lower-tourniquet group to achieve further bleeding reduction. Finally, the surgical effects of the two types were prospectively compared.Results: During the retrospective phase, patients in the lower-tourniquet group experienced more severe symptoms than did patients in the upper-tourniquet group, based on mean intraoperative blood loss (upper-tourniquet group 787.5 ml, lower-tourniquet group 1434.4 ml) intensive care unit admission rate (upper-tourniquet group 1.0%, lower-tourniquet group 33.3%), and length of hospital stay (upper-tourniquet group 10.2d, lower-tourniquet group 12.1d). During the prospective phase, after introduction of the revised surgical method involving forceps (in the lower-tourniquet group), the lower-tourniquet group exhibited improvements in the above indicators (intraoperative average blood loss 722.9 ml, intensive care unit admission rate 4.3%, hospital stays 9.0d). No increase in the rate of complications was observed.Conclusion: The relative positions of the placenta and tourniquet may influence the perioperative risk of severe placenta accreta spectrum. The method using a tourniquet (and forceps if necessary) can improve the surgical effect in cases of severe placenta accreta spectrum.

A public bicycle system (PBS) is a promising countermeasure for the traffic issues induced by rapid urbanization, and it is widely acknowledged that the built environment has a significant impact on the use of a PBS. However, as the urban built-up area expands, different regions within a city can exhibit diverse characteristics. The spatial effects and differences among regions have been neglected by existing studies. To better understand how the urban built environment affects PBS ridership, this study conducts a quantitative analysis of the spatial relationship. It introduces a multi-scale geographically weighted regression (MGWR) to accomplish this task and conducts and evaluates a case study of the PBS in Nanjing, China. Six types of “D” variables (density, diversity, design, destination accessibility, distance to transit, and demand management) are involved in the analysis. The proposed method outperforms linear regression and standard geographically weighted regression (GWR) in terms of explanatory power. The modeling results demonstrate different influencing patterns between traditional downtown areas and newly built-up areas, especially for the density of population, road network, parking space, and various points of interest.

A series of complex post-build heat treatment procedures are usually inevitable for selective laser melted (SLMed) Al-Si-Mg alloys, aiming to remove significant process-induced residual strains. In this work, we propose a new method to avoid the post-build heat treatment without compromising the mechanical properties in SLMed Al alloy A357. By heating up the build platform (up to 90 °C) during SLM fabrication or applying post heat treatment after SLM, the evolution of microstructure and mechanical properties for Al-7Si-0.6Mg alloy are compared at different conditions. Characterisations using scanning electron microscopy (SEM), X-ray Diffraction (XRD), transmission electron microscopy (TEM), and hardness tests suggest heating up the build platform is more effective in alleviating residual strain and resulting in uniform precipitates in the Al matrix. Tensile properties imply that SLMed A357 fabricated with a heated substrate possesses improved mechanical properties compared to SLMed A357 build on room temperature platforms and even with post-build heat treatment. Keywords: Selective laser melting, Al-Si-Mg alloys, Heat treatment, Residual strains, Mechanical properties

Selective Laser Melting (SLM) has received tremendous attentions due to its high degree of flexibility for the design and fabrication of geometrically complex parts. However, the majority of the currently applied metals for this advanced technology are still based on the traditional weldable and/or castable alloys, and the resulting mechanical properties of SLM fabricated samples are often mediocre. This is because the conventional alloys are not designed to accommodate the dynamic metallurgical characteristics of the SLM process and the benefits offered by SLM are not fully captured. In this study, an experimentally-based novel alloy development methodology utilising wedge mould casting and laser remelting is proposed, and the processability and properties of the developed alloys can be predicted for SLM. By mimicking the high solidification rate of the SLM process, unconventionally large amounts of solute were successfully placed into solution in the aluminium (Al) matrix. A high strength Al-Mn-Sc based alloy has been successfully developed and verified by SLM processing. The developed alloy possessed an average yield strength of about 430 MPa and a ductility of 21% in the as fabricated state, compared to approximately 570 MPa and 18% after direct ageing for 5 h at 300 °C, respectively. Keywords: Alloy development, Additive manufacturing, Selective laser melting, Aluminium alloy, Scandium

Objective: To study the chemical project risk management model by using BP neural network. Methods: Taking YYN chemical project as the study example, establish the risk management model through the study theories related to BP neural network, and conduct the application analysis. Results: Through the study, it's found that the design of management model in this study has a certain application value in the aspect of chemical project risk management. Conclusions: BP neural network is an important method for studying the chemical project risk management model, which is worthy of the study and analysis of related companies.

Direct laser fabrication (DLF) is one of the advanced near-net shape processing technologies. The variations of laser parameters can change the energy distribution within a laser scan, and thus affect the cooling rate, and resulting microstructure of deposited material. In this study, the effect of the laser parameters on the microstructure of additive laser fabricated Ti6Al4V alloy was investigated. It was found that huge columnar grains formed during laser fabrication of Ti6Al4V alloy for a wide range of processing conditions, and the laser power, scanning speed and duration time were had a significant effect on the refinement of the prior grains. Gradient morphologies were obtained from a complex thermal history.

In view of the importance of accurately measuring the relative density of a selective laser melted (SLMed) part for optimizing the selective laser melting (SLM) processing parameters, suitable procedures of the Archimedes method considering the surface-connected cavities were proposed by comparing the results using the Archimedes method with image analysis. The effects of the SLM processing parameters on the relative density of AlSi10Mg were investigated using the proposed procedures of the Archimedes methods and image analysis. Fourteen SLMed samples were produced by different SLM processing parameters according to Doehlert Matrix. The regression models correlating relative density and three SLM processing parameters (laser power, scan speed, and hatching distance) were built and the optimum parameter combination to get a high relative density was obtained. By plotting the response surfaces and contours of the regression models, it was found that the relative densities are both higher at the combination of the higher scan speed, higher power, and lower hatching distance and at the combination of a lower scan speed, a moderate laser power, and a optional hatching distance. It was also found that the parameter of hatching distance is the crucial parameter to get a high relative density and to get high mechanical property.

Functionally graded lattice structures produced by additive manufacturing are promising for bone tissue engineering. Spatial variations in their porosity are reported to vary the stiffness and make it comparable to cortical or trabecular bone. However, the interplay between the mechanical properties and biological response of functionally graded lattices is less clear. Here we show that by designing continuous gradient structures and studying their mechanical and biological properties simultaneously, orthopedic implant design can be improved and guidelines can be established. Our continuous gradient structures were generated by gradually changing the strut diameter of a body centered cubic (BCC) unit cell. This approach enables a smooth transition between unit cell layers and minimizes the effect of stress discontinuity within the scaffold. Scaffolds were fabricated using selective laser melting (SLM) and underwent mechanical and in vitro biological testing. Our results indicate that optimal gradient structures should possess small pores in their core (~900 µm) to increase their mechanical strength whilst large pores (~1100 µm) should be utilized in their outer surface to enhance cell penetration and proliferation. We suggest this approach could be widely used in the design of orthopedic implants to maximize both the mechanical and biological properties of the implant.

Located on the Pamir Plateau in Xinjiang Province, China, the Ji'erzankale Necropolis dates back to 2500 yr BP. Many materials that have been unearthed in this cemetery, including shoo konghou (musical instrument), bronze mirrors and glass beads, suggest cultural transference between East and West. Furthermore, small-sized and rounded fire altars made from sweet-scented Sabina were found for the first time and regarded as implements for fire veneration. We identified 70 wooden objects from 25 tombs within the Necropolis, and found that each object had been made from one of seven tree species. Analysis revealed that the inhabitants of the region mainly used the most widely available types of wood, namely Betula and Populus. People also specifically chose inflammable Populus wood to make hearth boards and hand drills (both are used for making fire by drilling), rigid Betula wood to craft wooden plates. Salix was used for fashioning wooden sticks, while sweet-scented Sabina was the preferred choice for making fire altars. Lonicera was selected for arrow shaft manufacture and Fraxinus syriaca, which has a beautiful grain, was chosen for making musical instruments. Conscious selection of different types of wood indicates that people of the Pamir Plateau were aware of the properties of various types of timbers, and were able to exploit these properties to the full. In turn, this demonstrates their wisdom and their ability to survive in, and adapt to, their local environment.

BACKGROUND: Conflicting reports support or refute an association between vitamin D deficiency with high levels of parathyroid hormone (PTH) and raised blood pressure or hypertension. OBJECTIVE: To explore the associations of serum vitamin D and PTH levels with blood pressure and risk of hypertension in a Chinese population. METHODS: A population-based cross-sectional study was conducted among 1,420 Chinese participants, aged 20-83 years, in 2010. Anthropometric phenotypes and blood pressure were evaluated. Serum lipids, 25-hydroxyvitamin D [25(OH)D] and PTH were measured. RESULTS: One thousand four hundred and twenty participants, including 566 women (39.9%), were evaluated in 2010. Four hundred and eighty seven were hypertensive (34.3%), of whom 214 (43.9%) received antihypertensive treatment. The median concentrations of serum 25(OH)D and PTH were 22.0 ng/ml and 2.83 pmol/l, respectively. Serum 25(OH)D and natural log of PTH levels were not independently associated with blood pressure in a multivariable adjusted linear regression analysis of 1,206 participants not receiving antihypertensive treatment (P>0.05). In logistic regression analyses, serum 25(OH)D levels were not associated with risk of hypertension in single and multiple regression models. One unit increments of natural log of PTH levels were significantly associated with risk of hypertension in the crude model (OR = 1.78, 95% confidence interval 1.38-2.28, P