All-optical interrogation of brain-wide activity in freely swimming larval zebrafish.

We introduce an all-optical technique that enables volumetric imaging of brain-wide calcium activity and targeted optogenetic stimulation of specific brain regions in unrestrained larval zebrafish. The system consists of three main components: a 3D tracking module, a dual-color fluorescence imaging module, and a real-time activity manipulation module. Our approach uses a sensitive genetically encoded calcium indicator in combination with a long Stokes shift red fluorescence protein as a reference channel, allowing the extraction of Ca2+ activity from signals contaminated by motion artifacts. The method also incorporates rapid 3D image reconstruction and registration, facilitating real-time selective optogenetic stimulation of different regions of the brain. By demonstrating that selective light activation of the midbrain regions in larval zebrafish could reliably trigger biased turning behavior and changes of brain-wide neural activity, we present a valuable tool for investigating the causal relationship between distributed neural circuit dynamics and naturalistic behavior.

Configuration Investigation, Structure Design and Deployment Dynamics of Rigid-Reflector Spaceborne Antenna with Deviation-Angle Panel.

Rigid-reflector spaceborne antennas (RRSAs) are well-suited for high-frequency application scenarios due to their high surface accuracy. However, the low stowing efficiency of RRSAs limits the aperture diameters and further deteriorates the electromagnetic (EM) performances in terms of gain, resolution and sensitivity. After conducting systematic feature analysis with respect to several typical RRSAs, we propose a novel type of RRSA to solve the aforementioned problems. Inspired by the pose adjustment process for a higher stowing efficiency of traditional RRSAs, we also propose a new segmentation scheme of a reflective surface consisting of a deviation-angle panel that facilitates a higher stowing efficiency. Based on this scheme, its corresponding folded configuration is implemented by combining Euler's rotation theorem and the idea of parameter identification. In addition, we also compare the stowing efficiency of different schemes to verify the high stowing efficiency of the configuration. Finally, we perform mechanism/structure design and deployment dynamics to demonstrate that the antenna can be successfully deployed and exhibits excellent deployment quality. The results suggest that the proposed antenna possesses higher stowing efficiency than that of the same kind, with a stable deployment and interference-free process.

Biomod2 modeling for predicting the potential ecological distribution of three Fritillaria species under climate change.

The Fritillaria species ranked as a well-known traditional medicine in China and has become rare due to excessive harvesting. To find reasonable strategy for conservation and cultivation, identification of new ecological distribution of Fritillaria species together with prediction of those responses to climate change are necessary. In terms of current occurrence records and bioclimatic variables, the suitable habitats for Fritillaria delavayi, Fritillaria taipaiensis, and Fritillaria wabuensis were predicted. In comparison with Maxent and GARP, Biomod2 obtained the best AUC, KAPPA and TSS values of larger than 0.926 and was chosen to construct model. Temperature seasonality was indicated to put the greatest influence on Fritillaria taipaiensis and Fritillaria wabuensis, while isothermality was of most importance for Fritillaria delavayi. The current suitable areas for three Fritillaria species were distributed in south-west China, accounting for approximately 17.72%, 23.06% and 20.60% of China's total area, respectively. During 2021-2100 period, the suitable habitats of F. delavayi and F. wabuensis reached the maximum under SSP585 scenario, while that of F. taipaiensis reached the maximum under SSP126 scenario. The high niche overlap among three Fritillaria species showed correlation with the chemical composition (P ≤ 0.05), while no correlation was observed between niche overlap and DNA barcodes, indicating that spatial distribution had a major influence on chemical composition in the Fritillaria species. Finally, the acquisition of species-specific habitats would contribute to decrease in habitat competition, and future conservation and cultivation of Fritillaria species.

Differential roles of Cassia tora 1-deoxy-D-xylulose-5-phosphate synthase and 1-deoxy-D-xylulose-5-phosphate reductoisomerase in trade-off between plant growth and drought tolerance.

Due to global climate change, drought is emerging as a major threat to plant growth and agricultural productivity. Abscisic acid (ABA) has been implicated in plant drought tolerance, however, its retarding effects on plant growth cannot be ignored. The reactions catalyzed by 1-deoxy-D-xylulose-5-phosphate synthase (DXS) and 1-deoxy-D-xylulose-5-phosphate reductoisomerase (DXR) proteins are critical steps within the isoprenoid biosynthesis in plants. Here, five DXS (CtDXS1-5) and two DXR (CtDXR1-2) genes were identified from Cassia tora genome. Based on multiple assays including the phylogeny, cis-acting element, expression pattern, and subcellular localization, CtDXS1 and CtDXR1 genes might be potential candidates controlling the isoprenoid biosynthesis. Intriguingly, CtDXS1 transgenic plants resulted in drought tolerance but retardant growth, while CtDXR1 transgenic plants exhibited both enhanced drought tolerance and increased growth. By comparison of ß-carotene, chlorophyll, abscisic acid (ABA) and gibberellin 3 (GA3) contents in wild-type and transgenic plants, the absolute contents and (or) altered GA3/ABA levels were suggested to be responsible for the balance between drought tolerance and plant growth. The transcriptome of CtDXR1 transgenic plants suggested that the transcript levels of key genes, such as DXS, 9-cis-epoxycarotenoid dioxygenases (NCED), ent-kaurene synthase (KS) and etc, involved with chlorophyll, ß-carotene, ABA and GA3 biosynthesis were induced and their contents increased accordingly. Collectively, the trade-off effect induced by CtDXR1 was associated with redesigning architecture in phytohormone homeostasis and thus was highlighted for future breeding purposes.

Aspartoacylase promotes the process of tumour development and is associated with immune infiltrates in gastric cancer.

BACKGROUND: Aspartoacylase (ASPA) is a gene that plays an important role in the metabolic reprogramming of cancer. However, the clinical relevance of ASPA in gastric cancer (GC) has not been demonstrated. METHODS: The link between ASPA and the clinical features of GC was determined using two public genomic databases. The multivariate Cox proportional hazard model and generalised linear regression model were applied to examine whether the ASPA level is associated with the prognosis and other pathological factors. In addition, the role of specific genes in the infiltration of immune cells in the setting of GC was investigated using a further immunological database. The expression level of various proteins was detected using a western blotting assay. Transwell and methyl thiazolyl tetrazolium tests were applied for the detection of cellular invasion and proliferation, with small hairpin ribonucleic acid used to knockdown ASPA. RESULTS: According to the multivariate Cox regression results, the down-regulated ASPA expression is a distinct prognostic factor. Furthermore, ASPA has significant positive correlations with the infiltration of immune cells in GC lesions. Compared to the non-cancer tissues, the GC tissues had a significantly lower level of ASPA expression (p < 0.05). Using knockdown and overexpression techniques, it was demonstrated that ASPA affects the capacity of cell lines for GC to both proliferate and invade. CONCLUSION: Overall, ASPA could promote the occurrence and development of GC and presents a promising predictive biomarker for the disease since it is favourably connected with immune infiltrates and negatively correlated with prognosis.

Mitochondrial Calcium Nanoregulators Reverse the Macrophage Proinflammatory Phenotype Through Restoring Mitochondrial Calcium Homeostasis for the Treatment of Osteoarthritis.

Introduction: Osteoarthritis (OA) is a chronic degenerative joint disease accompanied by an elevated macrophage proinflammatory phenotype, which is triggered by persistent pathologically elevated calcium ion levels in mitochondria. However, existing pharmacological compounds targeting the inhibition of mitochondrial calcium ion (m[Ca2+]) influx are currently limited in terms of plasma membrane permeability and low specificity for ion channels and transporters. In the present study, we synthesized mesoporous silica nanoparticle-amidated (MSN)-ethylenebis (oxyethylenenitrilo)tetraacetic acid (EGTA)/triphenylphosphine (TPP)-polyethylene glycol (PEG) [METP] nanoparticles (NPs), which specifically target mitochondria and block excess calcium ion influx. Methods: m[Ca2+] overload in OA mouse bone marrow-derived macrophages (BMDMs) was detected by a fluorescence probe. A tissue in situ fluorescence colocalization assay was used to evaluate METP NP uptake by macrophages. BMDMs from healthy mice were pretreated with a concentration gradient of METP NPs followed by lipopolysaccharide (LPS) stimulation and detection of m[Ca2+] levels in vitro. The optimal METP NP concentration was further applied, and the endoplasmic reticulum (ER) and cytoplasm calcium levels were detected. The inflammatory phenotype was measured by surface markers, cytokine secretion and intracellular inflammatory gene/protein expression. A Seahorse cell energy metabolism assay was performed to elucidate the mechanism by which METP NPs reverse the BMDM proinflammatory phenotype. Results: The present study identified calcium overload in BMDM mitochondria of OA mice. We demonstrated that METP NPs reversed the increased m[Ca2+] levels in mitochondria and the proinflammatory phenotype of BMDMs, with both in vivo and in vitro experiments, via the inhibition of the mitochondrial aspartate-arginosuccinate shunt and ROS production. Conclusion: We demonstrated that METP NPs are effective and highly specific regulators of m[Ca2+] overload. In addition, we demonstrated that these METP NPs reverse the macrophage proinflammatory phenotype by restoring m[Ca2+] homeostasis, thereby inhibiting the tissue inflammatory response and achieving a therapeutic effect for OA.

Assessment of Low Back Pain in Helicopter Pilots Using Electrical Bio-Impedance Technique: A Feasibility Study.

Low back pain (LBP) is known to pose a serious threat to helicopter pilots. This study aimed to explore the potential of electrical bio-impedance (EBI) technique with the advantages of no radiation, non-invasiveness and low cost, which is intended to be used as a daily detection tool to assess LBP in primary aviation medical units. The LBP scales (severity) in 72 helicopter pilots were assessed using a pain questionnaire, while the bilateral impedance measurements of the lumbar muscle were carried out with a high precision EBI measurement system. Results showed that the modulus of lumbar muscle impedance increased with LBP scale whereas the phase angle decreased. For different LBP scales, significant differences were found in the modulus of lumbar muscle impedance sum on both sides (Z sum ), as well as in the modulus and phase angle of lumbar muscle impedance difference between both sides (Z diff and ϕ diff ), respectively (P < 0.05). Moreover, Spearman's correlation analysis manifested a strong correlation between Z sum and LBP scale (R = 0.692, P < 0.01), an excellent correlation between Z diff and LBP scale (R = 0.86, P < 0.01), and a desirable correlation between ϕ diff and LBP scale (R = -0.858, P < 0.01). In addition, receiver operator characteristic analysis showed that for LBP prediction, the area under receiver operator characteristic curve of Z sum , Z diff , and ϕ diff were 0.931, 0.992, and 0.965, respectively. These findings demonstrated that EBI could sensitively and accurately detect the state of lumbar muscle associated with LBP, which might be the potential tool for daily detection of LBP in primary aviation medical units.

Modeling of the Potential Geographical Distribution of Three Fritillaria Species Under Climate Change.

Fritillaria species, a well-known Chinese traditional medicine for more than 2,000 years, have become rare resources due to excessive harvesting. In order to balance the economical requirement and ecological protection of Fritillaria species, it is necessary to determine (1) the important environmental variables that were responsible for the spatial distribution, (2) distribution change in response to climate change in the future, (3) ecological niche overlap between various Fritillaria species, and (4) the correlation between spatial distribution and phylogenies as well. In this study, the areas with potential ecological suitability for Fritillaria cirrhosa, Fritillaria unibracteata, and Fritillaria przewalskii were predicted using MaxEnt based on the current occurrence records and bioclimatic variables. The result indicated that precipitation and elevation were the most important environmental variables for the three species. Moreover, the current suitable habitats of F. cirrhosa, F. unibracteata, and F. przewalskii encompassed 681,951, 481,607, and 349,199 km2, respectively. Under the scenario of the highest concentration of greenhouse gas emission (SSP585), the whole suitable habitats of F. cirrhosa and F. przewalskii reach the maximum from 2021 to 2100, while those of F. unibracteata reach the maximum from 2021 to 2100 under the scenario of moderate emission (SSP370) from 2021 to 2100. The MaxEnt data were also used to predict the ecological niche overlap, and thus high overlap occurring among three Fritillaria species was observed. The niche overlap of three Fritillaria species was related to the phylogenetic analysis despite the non-significance (P > 0.05), indicating that spatial distribution was one of the factors that contributed to the speciation diversification. Additionally, we predicted species-specific habitats to decrease habitat competition. Overall, the information obtained in this study provided new insight into the potential distribution and ecological niche of three species for the conservation and management in the future.

Effects of positive acceleration (+Gz stress) on liver enzymes, energy metabolism, and liver histology in rats.

BACKGROUND: Exposure to high sustained +Gz (head-to-foot inertial load) is known to have harmful effects on pilots' body in flight. Although clinical data have shown that liver dysfunction occurs in pilots, the precise cause has not been well defined. AIM: To investigate rat liver function changes in response to repeated +Gz exposure. METHODS: Ninety male Wistar rats were randomly divided into a blank control group (BC group, n = 30), a +6 Gz/5 min stress group (6GS group, n = 30), and a +10 Gz/5min stress group (10GS group, n = 30). The 6GS and 10GS groups were exposed to +6 Gz and +10 Gz, respectively, in an animal centrifuge. The onset rate of +Gz was 0.5 G/s. The sustained time at peak +Gz was 5 min for each exposure (for 5 exposures, and 5-min intervals between exposures for a total exposure and non-exposure time of 50 min). We assessed liver injury by measuring the portal venous flow volume, serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST), liver tissue malondialdehyde (MDA), Na+-K+-ATPase, and changes in liver histology. These parameters were recorded at 0 h, 6 h, and 24 h after repeated +Gz exposures. RESULTS: After repeated +Gz exposures in the 6GS and the 10GS groups, the velocity and flow signal in the portal vein (PV) were significantly decreased as compared to the BC group at 0 h after exposure. Meanwhile, we found that the PV diameter did not change significantly. However, rats in the 6GS group had a much higher portal venous flow volume than the 10GS group at 0 h after exposure. The 6GS group had significantly lower ALT, AST, and MDA values than the 10GS group 0 h and 6 h post exposure. The Na+-K+-ATPase activity in the 6GS group was significantly higher than that in the 10GS group 0 h and 6 h post exposure. Hepatocyte injury, determined pathologically, was significantly lower in the 6GS group than in the 10GS group. CONCLUSION: Repeated +Gz exposures transiently cause hepatocyte injury and affect liver metabolism and morphological structure.

The synergistic effect of nanotopography and sustained dual release of hydrophobic and hydrophilic neurotrophic factors on human mesenchymal stem cell neuronal lineage commitment.

A combination of nanotopography and controlled release is a potential platform for neuronal tissue engineering applications. Previous studies showed that combining both physical and chemical guidance was more effective than individual cues in the directional promotion of neurite outgrowth. Nanotopography can direct human mesenchymal stem cells (hMSCs) into neuronal lineage, while controlled release of neurotrophic factors can deliver temporally controlled biochemical signals. Hypothesizing that the synergistic effect will enhance neuronal lineage commitment of hMSCs, a fabrication method for multiple neurotrophic factors delivery from a single nanopatterned (350 nm gratings), poly-ɛ-caprolactone (PCL) film was developed and evaluated. Our results showed a synergistic effect on hMSC differentiation cultured on substrates with both nanotopographical and biochemical cues. The protein/drug encapsulation into PCL nanopatterned films was first optimized using a hydrophilic model protein, bovine serum albumin. The hydrophobic retinoic acid (RA) molecule was directly incorporated into PCL films. To achieve sustained release, hydrophilic nerve growth factor (NGF) was first encapsulated within polyelectrolyte complexation fibers before they were embedded within the nanopatterned PCL film. Our results showed that nanotopography on the fabricated polymer films remained intact, while release of bioactive RA and NGF was sustained over a period of 3 weeks. Under the combinatorial effect of physical and biochemical cues, we observed an enhanced upregulation of neuronal genes such as microtubule-associated protein 2 (MAP2) and neurofilament light (NFL) as compared with sustained delivery of individual cues and bolus delivery. Quantitative polymerase chain reaction analysis showed that MAP2 and NFL gene upregulation in hMSCs was most pronounced on the nanogratings with sustained release of both RA and NGF. The fabricated platforms supported the sustained delivery of multiple neurotrophins, including both hydrophobic and hydrophilic therapeutic agents, while providing surface patterning versatility for application in neural regeneration and tissue engineering.

Computational fluid model incorporating liver metabolic activities in perfusion bioreactor.

The importance of in vitro hepatotoxicity testing during early stages of drug development in the pharmaceutical industry demands effective bioreactor models with optimized conditions. While perfusion bioreactors have been proven to enhance mass transfer and liver specific functions over a long period of culture, the flow-induced shear stress has less desirable effects on the hepatocytes liver-specific functions. In this paper, a two-dimensional human liver hepatocellular carcinoma (HepG2) cell culture flow model, under a specified flow rate of 0.03 mL/min, was investigated. Besides computing the distribution of shear stresses acting on the surface of the cell culture, our numerical model also investigated the cell culture metabolic functions such as the oxygen consumption, glucose consumption, glutamine consumption, and ammonia production to provide a fuller analysis of the interaction among the various metabolites within the cell culture. The computed albumin production of our 2D flow model was verified by the experimental HepG2 culture results obtained over 3 days of culture. The results showed good agreement between our experimental data and numerical predictions with corresponding cumulative albumin production of 2.9 × 10(-5) and 3.0 × 10(-5) mol/m(3) , respectively. The results are of importance in making rational design choices for development of future bioreactors with more complex geometries.

Computational fluid modeling and performance analysis of a bidirectional rotating perfusion culture system.

A myriad of bioreactor configurations have been investigated as extracorporeal medical support systems for temporary replacement of vital organ functions. In recent years, studies have demonstrated that the rotating bioreactors have the potential to be utilized as bioartificial liver assist devices (BLADs) owing to their advantage of ease of scalability of cell-culture volume. However, the fluid movement in the rotating chamber will expose the suspended cells to unwanted flow structures with abnormally high shear conditions that may result in poor cell stability and in turn lower the efficacy of the bioreactor system. In this study, we compared the hydrodynamic performance of our modified rotating bioreactor design with that of an existing rotating bioreactor design. Computational fluid dynamic analysis coupled with experimental results were employed in the optimization process for the development of the modified bioreactor design. Our simulation results showed that the modified bioreactor had lower fluid induced shear stresses and more uniform flow conditions within its rotating chamber than the conventional design. Experimental results revealed that the cells within the modified bioreactor also exhibited better cell-carrier attachment, higher metabolic activity, and cell viability compared to those in the conventional design. In conclusion, this study was able to provide important insights into the flow physics within the rotating bioreactors, and help enhanced the hydrodynamic performance of an existing rotating bioreactor for BLAD applications.

A thin-walled polydimethylsiloxane bioreactor for high-density hepatocyte sandwich culture.

In vitro drug testing requires long-term maintenance of hepatocyte liver specific functions. Hepatocytes cultured at a higher seeding density in a sandwich configuration exhibit an increased level of liver specific functions when compared to low density cultures due to the better cell to cell contacts that promote long term maintenance of polarity and liver specific functions. However, culturing hepatocytes at high seeding densities in a standard 24-well plate poses problems in terms of the mass transport of nutrients and oxygen to the cells. In view of this drawback, we have developed a polydimethylsiloxane (PDMS) bioreactor that was able to maintain the long-term liver specific functions of a hepatocyte sandwich culture at a high seeding density. The bioreactor was fabricated with PDMS, an oxygen permeable material, which allowed direct oxygenation and perfusion to take place simultaneously. The mass transport of oxygen and the level of shear stress acting on the cells were analyzed by computational fluid dynamics (CFD). The combination of both direct oxygenation and perfusion has a synergistic effect on the liver specific function of a high density hepatocyte sandwich culture over a period of 9 days.

[Effects of NaCl stress on Hippophae rhamnoides and Shepherdia argentea seedlings growth and photosynthetic characteristics].

With two-year old seedlings of Hippophea rhamnoides and Shepherdia argentea as test materials, this paper studied their growth and photosynthetic characteristics under the stress of different concentration (0, 200, 400 and 600 mmol x L(-1)) NaCl. The results showed that the biomass and total leaf area per plant of H. rhamnoides and S. argentea seedlings decreased significantly with increasing NaCl concentration. Comparing with the control, the root/shoot ratio of H. rhamnoides and S. argentea seedlings under NaCl stress increased obviously, while the leaf mass per area (LMA) decreased slightly. When the NaCl concentration increased and the stress time prolonged, the net photosynthetic rate (P(n)), transpiration rate (T(r)), and stomatal conductance (G(s)) of H. rhamnoides and S. argentea seedlings declined markedly, the intercellular CO2 concentration (C(i)) increased after an initial decrease, whereas the water use efficiency (WUE) and stomatal limiting value (L(s)) decreased after an initial increase. The dynamic changes of G(s), C(i) and L(s) indicated that the decline of P(n) was mainly caused by the stomatal limitation in a short-term stress, and by non-stomatal limitation in a long-term stress. The poorer the salt tolerance of tree species and the higher the NaCl concentration, the earlier the transition from stomatal limitation to non-stomatal limitation would occur. As for H. rhamnoides, its morphological symptoms of salt injury appeared on the 10th day, and all of its seedlings were died on the 22th day under 600 mmol NaCl x L(-1) stress. In contrast, S. argentea could tolerate 600 mmol NaCl x L(-1) stress for above 30 days, illustrating that S. argentea, as an introduced tree species, had higher salt tolerance than H. rhamnoides, and could be planted widely in saline regions of China.