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•A design method of nonlinear periodically gradient porous structure is proposed.•The compression failure mechanism of the nonlinear porous structure was analyzed by digital image ...correlation technology and finite element analysis, and a periodic failure deformation was observed.•The strain-stress plateau length and effective energy absorption were improved by increasing the number of porosity cycles.
This research presents a design method of the nonlinear periodic gradient triply periodic minimal surface structures (NL-TPMS). The gradient porosity of NL-TPMS was controlled by a sinusoidal function and the influence of the number of cycles on the compression failure mechanism has been investigated. Homogenous TPMS and NL-TPMS were manufactured by laser powder bed fusion (LPBF) with 316L stainless steel powder. Digital image correlation (DIC) and finite element analysis (FEA) were applied to explore the compression behavior of NL-TPMS. The strain of the plateau end of homogenous TPMS decreases as the porosity increases, and the DIC results show that homogenous TPMS deformed with a 45° diagonal shear band. The compression results show that anisotropy of mechanical properties exists in NL-TPMS. The length of the first plateau and compressive proof strength increase as the number of cycles of porosity increases. The cycle of gradient porosity also influences the compression behavior of NL-TPMS, and a periodic failure deformation was observed in the NL-TPMS rather than a layer-by-layer compression deformation in normal gradient porous structures. The maximum principal strain of NL-TPMS detected by DIC presents a periodic distribution, which corresponds to the sinusoidal period designed function of NL-TPMS.
Primulina Hance is an emerging model for studying evolutionary divergence, adaptation and speciation of the karst flora. However, phylogenetic relationships within the genus have not been resolved ...due to low variation detected in the cpDNA regions. Chloroplast genomes can provide important information for phylogenetic and population genetic studies. Recent advances in next-generation sequencing (NGS) techniques greatly facilitate sequencing whole chloroplast genomes for multiple individuals. Consequently, novel strategies for development of highly polymorphic loci for population genetic and phylogenetic studies based on NGS data are needed.
For development of high polymorphic loci for population genetic and phylogenetic studies, two novel strategies are proposed here. The first protocol develops lineage-specific highly variable markers from the true high variation regions (Con_Seas) across whole cp genomes, instead of traditional noncoding regions. The pipeline has been integrated into a single perl script, and named "Con_Sea_Identification_and_PIC_Calculation". The second method assembles chloroplast fragments (poTs) and sub-super-marker (CpContigs) through our "SACRing" pipeline. This approach can fundamentally alter the strategies used in phylogenetic and population genetic studies based on cp markers, facilitating a transition from traditional Sanger sequencing to RAD-Seq. Both of these scripts are available at https://github.com/scbgfengchao/ .
Three complete Primulina chloroplast genomes were assembled from genome survey data, and then two novel strategies were developed to yield highly polymorphic markers. For experimental evaluation of the first protocol, a set of Primulina species were used for PCR amplification. The results showed that these newly developed markers are more variable than traditional ones, and seem to be a better choice for phylogenetic and population studies in Primulin a. The second method was also successfully applied in population genetic studies of 21 individuals from three natural populations of Primulina.
These two novel strategies may provide a pathway for similar research in other non-model species. The newly developed high polymorphic loci in this study will promote further the phylogenetic and population genetic studies in Primulina and other genera of the family Gesneriaceae.
Cadmium, a widespread toxic heavy metal in farmland soils, is harmful to human health. A field experiment was conducted to investigate the effects of biochar and biochar-based fertilizers on soil pH, ...organic matter, and available Cd, as well as rice Cd uptake and translocation. The results showed that rice biomass was significantly increased after both the application of biochar and high rate of biochar-based fertilizers at the tillering stage. The biomass and plant height of rice were improved at filling and maturity stages. Soil pH was significantly increased with the application of biochar but not with the biochar-based fertilizer. The amendments of biochar and biochar-based fertilizers had no significant (
p
< 0.05) influence on soil organic matter content. The concentration of available Cd in soil and the concentration of Cd in rice were decreased with the application of different amounts of biochar and biochar-based fertilizers in the mature stage. However, this effect was much greater under biochar amendment. Compared to the control, the concentration of available Cd in soil was reduced by 33.09% with the low application rate of biochar, while that was reduced by 18.06% with the high application rate of biochar. The lowest bioaccumulation factor was due to the high concentration of biochar and biochar-based fertilizers. It is concluded that biochar and biochar-based fertilizers particularly at a high addition rate are appropriate for decreasing Cd mobility and improve soil quality for contaminated paddy soils. The study showed a method for the safe production of rice in Cd-polluted farmlands by using a high application rate of biochar or carbon-based fertilizers.
B-1 lymphocytes exhibit specialized roles in host defense against multiple pathogens. Despite the fact that CD19
+
CD93
+
B220
lo/-
B cells have been identified as B-1 progenitors, the definition for ...B-1 progenitors remains to be elucidated as CD19
+
CD93
+
B220
+
B cells are capable to give rise to B-1 cells. Given that transcription factor Bhlhe41 is highly and preferentially expressed in B-1 cells and regulates B-1a cell development, we generated a transgenic mouse model,
Bhlhe41
dTomato-Cre
, for fate mapping and functional analysis of B-1 cells.
Bhlhe41
dTomato-Cre
mice efficiently traced Bhlhe41 expression, which was mainly restricted to B-1 cells in B-cell lineage. We showed an efficient and specific Cre-mediated DNA recombination in adult B-1 cells and neonatal B-1 progenitors rather than B-2 cells by flow cytometric analysis of
Bhlhe41
dTomato-Cre/+
Rosa26
EYFP
mice. Treatment of
Bhlhe41
dTomato-Cre/+
Rosa26
iDTR
mice with diphtheria toxin revealed a robust efficacy of B-1 cell depletion. Interestingly, using
Bhlhe41
dTomato-Cre
mice, we demonstrated that neonatal B-1 progenitors (CD19
+
CD93
+
B220
lo/-
) expressed Bhlhe41 and were identical to well-defined transitional B-1a progenitors (CD19
+
CD93
+
B220
lo/-
CD5
+
), which only gave rise to peritoneal B-1a cells. Moreover, we identified a novel population of neonatal splenic CD19
hi
dTomato
+
B220
hi
CD43
lo
CD5
lo
B cells, which differentiated to peritoneal B-1a and B-1b cells.
Bhlhe41
deficiency impaired the balance between CD19
hi
dTomato
+
B220
lo/-
CD5
hi
and CD19
hi
dTomato
+
B220
hi
CD5
lo
cells. Hence, we identified neonatal CD19
hi
dTomato
+
B220
hi
CD43
lo
CD5
lo
B cells as novel transitional B-1 progenitors.
Bhlhe41
dTomato-Cre/+
mouse can be used for fate mapping and functional studies of B-1 cells in host-immune responses.
•The prevalence of lifetime major depressive disorder (MDD) and current MDD were high among HIV-positive individuals in Guangdong, China.•AIDS diagnosis, decreased social support, and more negative ...life events were risk factors of MDD.•Intervention targeting individuals with MDD or with a high risk of MDD should be adopted to address the need of mental health among HIV-positive individuals in Guangdong, China.
People living with HIV may suffer from mental disorders. We aimed to explore the prevalence of and factors associated with major depressive disorder (MDD) among HIV-positive individuals in Guangdong, China, about which little is known.
A cross-sectional study was conducted to recruit HIV-positive individuals from the Centers for Disease Prevention and Control of Guangzhou, Zhongshan, and Yangjiang from September 2007 to September 2008. Data were collected by questionnaires. MDD was diagnosed and assessed by two psychiatrists using the Structured Clinical Interview for DSM-IV-TR Axis I Disorders-Patient Edition (SCID-I/P) based on the DSM-IV criteria. Multiple logistic regression analyses were conducted to explore the factors associated with MDD.
The prevalences of lifetime MDD and current MDD among the 339 included participants were 22.71% (95% confidence interval CI: 18.25–27.17%) and 12.09% (95%CI: 8.62%–15.57%), respectively. The results of multiple logistic regression showed that patients with AIDS had a higher risk of lifetime MDD (odds ratio OR = 2.69, 95%CI: 1.38–5.26) and current MDD (OR = 3.51, 95%CI: 1.59–7.75) than HIV-infected individuals. Participants with more number of negative life events were more likely to have lifetime MDD (OR = 2.33, 95%CI: 1.34–4.06) and current MDD (OR = 3.77, 95%CI: 1.76–8.09) than individuals with fewer negative life events. Individuals with higher score of social support were less likely to have lifetime MDD (OR = 0.45, 95%CI: 0.26–0.80) and current MDD (OR = 0.46, 95%CI: 0.21–0.97) than individuals with less social support.
The prevalence of MDD was high among HIV-positive individuals in China. AIDS diagnosis, decreased social support, and an increased number of negative life events were risk factors for MDD.
As an effective driven mechanism proved experimentally, rotating electroosmotic (EO) micropump has attracted the attentions of many researchers in recent years. In this article, an exact solution of ...transient rotating EO flow with time-fractional Caputo-Fabrizio derivative through a slit microchannel is obtained by using Laplace transform method. It is interesting to find from computational results that with the increase of fractional parameter α (0<α<1), the time required to attain steady velocity becomes shorter and the oscillating phenomenon becomes more pronounced.
This paper is to investigate the J-selfadjointness of a class of high-order complex coefficients differential operators with transmission conditions. Using the Lagrange bilinear form of J-symmetric ...differential equations, the definition of J-selfadjoint differential operators and the method of matrix representation, we prove that the operator is J-selfadjoint operator, and the eigenvectors and eigen-subspaces corresponding to different eigenvalues are C-orthogonal.
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•Physicochemical properties of CNPs became stable with increasing stewing time.•CNPs were the most sensitive to amylase and the least sensitive to protease.•Triglyceride-coated ...protein is in the center of CNPs with outer phospholipid bilayer.
Colloidal nanoparticles (CNPs), as carriers of nutrients, naturally exist in food or form during cooking. In this study, the colloidal properties, structures, rheological properties, and chemical composition location of CNPs were analyzed during 15 min to 5 h lamb soup stewing. With the increasing stewing time, the particle size and absolute value of the zeta potential of CNPs increased, indicating that CNPs became more stable. As the stewing time increased, the blue-shifted Fourier transform infrared spectroscopy absorption peaks and the red-shifted fluorescence spectroscopy absorption peaks certificated the structural changes in CNPs. And α-helix and β-turn content decreased, while β-sheet and random coil content increased in processing, potentially resulting in the opening CNPs structures. In addition, our findings revealed that proteins were encapsulated within the lipids in the inner part, while carbohydrates were dispersed in the outermost layers of the CNPs with a phospholipid bilayer.
Purpose
The purpose of this study is focused on the mechanical properties of multi-materials porous structures manufactured by selective laser melting (SLM).
Design/methodology/approach
The Diamond ...structure was designed by the triply periodic minimal surface function in MATLAB, and multi-materials porous structures were manufactured by SLM. Compression tests were applied to analyze the anisotropy of mechanical properties of multi-materials porous structures.
Findings
Compression results show that the multi-materials porous structure has a strong anisotropy behavior. When the compression force direction is parallel to the material arrangement, multi-materials porous structure was compressed in a layer-by-layer way, which is the traditional deformation of the gradient structure. However, when the compression force direction is perpendicular to the material arrangement, the compression curves show a near-periodic saw-tooth waveform characteristic, and this kind of structure was compressed consistently. It is demonstrated that the combination with high strength brittle material and low strength plastic material improves compression mode, and plastic material plays a role in buffering fracture.
Originality/value
This research provides a new method for the design and manufacturing of multi-materials porous structures and an approach to change the compression behavior of the porous structure.
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