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The purpose of this study is to investigate the effect of TiB2 content on the microstructure and wear behavior of nano-TiB2p/2024Al composites fabricated by laser direct energy deposition (L-DED). The dry sliding friction and wear behavior was evaluated using a ball-on-disk tribometer by sliding samples against a 6-mm diameter GCr15 (AISI52100) steel ball under applied loads of 2.2 N at room temperature. Microstructural characterization of the as-deposited 2024Al alloy showed the presence of oriented columnar grains. Once 3 wt% TiB2 particles were introduced, the as-deposited microstructure consisted of a mixture of columnar and equiaxed grains. It was found that the addition of TiB2 particles can significantly improve the wear resistance of L-DEDed 2024Al. For instance, the wear-rate of an 8 wt% TiB2p/2024Al matrix composite with full equiaxed grains is almost 20 times lower than that of the unreinforced alloy. A grain morphology-induced wear mechanism for the L-DEDed TiB2p/2024Al composites is proposed and is dominated by mutual oxidation and abrasive wear. The research results are beneficial to understand the wear mechanism of L-DEDed nano-TiB2p/2024Al matrix composites and can also provide theoretical guidance for the selection of TiB2 content.

To evaluate the effects of miR-29a on the high glucose (HG)-induced apoptosis and the correlation between miR-29a and heme oxygenase-1 (HO-1) and the underlying molecular mechanism.The cell apoptosis was analyzed by the flow cytometry, and the cells autophagy was evaluated using the transmission electron microscopy. Luciferase reporter assay was carried out to detect the correlation between miR-29a and HO-1. Besides, reverse transcription-PCR and Western blot were applied to detect the mRNA and protein levels.The expression of miR-29a was significantly decreased in the HG-treated podocytes. Besides, miR-29a overexpression could promote cellular autophagy and significantly reduce HG-induced podocytes apoptosis. Moreover, HO-1 was a direct target of miR-29a and the pre-autophagy and the anti-apoptotic effects of miR-29a on HG-treated podocytes could be significantly reversed by the HO-1 siRNA administration.MiR-29a functionally promoted podocytes autophagy and inhibited apoptosis through the HO-1dependent pathway in the HG condition.

SynopsisObjectives Salidroside, the predominant component of a Chinese herbal medicine, Rhodiola rosea L., becomes an attractive bio-agent due to its multifunction. Although it is well proposed that this herbal medicine may have photoprotective effect according to the folk hearsay, the direct supportive experimental evidences linking the drug with skin ageing have rarely been reported so far. The study was conducted to investigate the photoprotective role of salidrosdie and its related mechanisms in vitro. Methods First, a premature senescence model induced by UVB irradiation (250 mJ cm−2) in human dermal fibroblasts (HDFs) was established, and senescent phenotypes were evaluated by cell morphology, cell proliferation, senescence-associated beta-galactosidase (SA-β-gal) activity and cell cycle distribution. Then the photoprotective effect of salidroside was investigated. Cells were pre-treated with various doses of salidroside (1, 5 and 10 μM) followed by the sublethal dosage of UVB exposure and then were harvested for various detections, including senescence-associated phenotypes and molecules, alteration of oxidative stress, matrix metalloproteinase-1 (MMP-1) secretion and inflammatory response. Results Pre-treatment of salidroside dose dependently reversed the senescent state of HDFs induced by UVB as evidenced by elevated cell viability, decreased SA-β-gal activity and relieving of G1/G0 cell cycle arrest. UVB-induced increased protein expression of cyclin-dependent kinase (CDK) inhibitors p21WAF1 and p16INK4 was also repressed by salidrosdie treatment in a dose-dependent manner. Meanwhile, the increment of malondialdehyde (MDA) level in UVB-irradiated HDFs was inhibited upon salidroside treatment. Additionally, salidroside significantly attenuated UVB-induced synthesis of MMP-1 as well as the production of IL-6 and TNF-α in HDFs. Conclusion Our data provided the evidences for the protective role of salidroside against UVB-induced premature senescence in HDFs probably via its anti-oxidative property and inhibition on production of MMP-1 and pro-inflammatory cytokines, which indicated its potential utilization as an active ingredient in the preparation of photoprotective formulation.

Atractylodes chinensis (DC.) Koidz. is a perennial medicinal plant in the Compositae family in China. The dried roots have medicinal functions of invigorating the spleen, dispelling wind, and improving eyesight. Anthracnose-like symptoms were observed on the leaves and stems of a 2-year-old A. chinensis landrace in Changli County, Hebei Province, from July to September in 2017. In the field, small, round dark-brown spots appeared on the leaves and stems at the beginning. Later, the lesions on the leaves expanded to irregular spots, slightly sunken, grayish brown to grayish white in the center, and dark brown on the edge. The lesions on the stems spread from the spot to circle around the whole stem. Eventually, the whole plant started to wither and die. The incidence was as high as 30% in 2017. Symptomatic tissues from leaves were cut into 0.2- to 0.5-mm² squares and stems were cut into 0.5- to 1-cm lengths; they were surface disinfested with 70% ethanol, rinsed with sterile distilled water, and then cultured on potato dextrose agar (PDA) at 25°C with a 12-h light regime. Seven Colletotrichum-like isolates were obtained with a frequency of 79%. Colonies on PDA were initially pale, gradually turning black after 3 days, with obvious ring patterns and less aerial mycelium (colonies were 3.25 cm in diameter). Conidia ranged from 15.6 to 23.2 μm long (mean 19.4 μm) × 2.5 to 4.8 μm wide (mean 3.6 μm). Conidia were aseptate, hyaline, smooth, scythe or crescent with oil droplets, curving with tapered ends and a truncated base. Conidial length/width ratio was 3.0 to 6.0. Chlamydospores were dark brown, globose to subglobose, in chains and clusters. Setae were straight, dark brown, and septate. The isolates were further characterized by sequencing of internal transcribed spacer (ITS), actin, β-tubulin, and glyceraldehyde 3-phosphate dehydrogenase (GAPDH) genes. The sequences of the isolates (GenBank accession nos. MH290362 for ITS, MH935512 for actin, MH935514 for β-tubulin, and MH935513 for GAPDH) showed 99 to 100% similarity with Colletotrichum chlorophyti in GenBank (JX126475 for ITS, GU227993 for actin, JX126477 for β-tubulin, and GU228286 for GAPDH). Phylogenetic analysis showed the fungal isolates were grouped into the clade with C. chlorophyti. The fungi were identified as C. chlorophyti on the basis of morphological characteristics and sequence analysis. A pathogenicity test was conducted on 2-year-old A. chinensis. Twenty leaves and 20 stems were inoculated with 5-mm-diameter plugs from a 7-day-old culture in moist Petri dishes for 7 days at 25°C with a 12-h photoperiod, with PDA plugs serving as the control. The inoculated leaves and stems exhibited similar symptoms to the original field plants. However, there were no symptoms on control plants. The pathogen was reisolated from infected leaves and stems, confirming Koch’s postulates. This fungus previously has been reported as the pathogen of soybean anthracnose, moringa anthracnose, and soybean seed anthracnose (Cai et al. 2016; Yang et al. 2012, 2013). To our knowledge, this is the first report of C. chlorophyti causing anthracnose of A. chinensis in China. The disease poses a threat to production of A. chinensis, and this new finding is important in the diagnosis and management in field production.

The crystallized cubic boron nitride (c-BN) films have been grown on silicon (100) wafer substrate successfully at room temperature by using a pulsed plasma enhanced chemical vapor deposition technique. Infrared absorption spectra and x-ray diffraction indicate that deposited boron nitride films mainly consist of c-BN phase. The scanning electron microscopy images exhibit regular grain shapes. The mean grain size is about 500 nm. The ratio of c-BN phase to h-BN phase in the deposited thin films mainly depends on the discharging voltages that producing the pulsed plasma.

In most earlier experimental investigations of condensation on low-fin tubes, vapor-side heat transfer coefficients have been found from overall (vapor-to-coolant) measurements using either predetermined coolant-side correlations or “Wilson plot” methods. When the outside resistance dominates, or is a significant proportion of the overall resistance, these procedures can give satisfactory accuracy. However, for externally enhanced tubes, and particularly with high-conductivity fluids such as water, significant uncertainties may be present. In order to provide reliable, high-accuracy data, to assist in the development of theoretical models, tests have been conducted using specially constructed plain and finned tubes fitted with thermocouples to measure the tube wall temperature, and hence the vapor-side heat transfer coefficient, directly. The paper describes the technique for manufacturing the tubes and gives results of systematic heat transfer measurements covering the effects of fin height, thickness, and spacing, tube diameter, and vapor velocity. The tests were carried out with steam, ethylene glycol, and R-113, with vertical vapor downflow. The heat flux was measured using an accurately calibrated 10-junction thermopile and paying particular attention to coolant mixing and isothermal immersion of thermocouple junctions. Care was taken to avoid errors due to the presence in the vapor of noncondensing gas and the occurrence of dropwise condensation. Smooth, consistent, and repeatable results were obtained in all cases. The data are presented in easily accessible form and are compared with the results of previous investigations, where indirect methods were used to determine the vapor-side data, and with theory.

Relativistic mono‐energetic electron beams have been demonstrated by worldwide laser‐plasma accelerator experiments in the range of a few tens TW. Laser‐plasma accelerator experiment has been carried out with 200TW, 30fs Ti:Sapphire laser pulses focused on helium gas‐jets with F/8.7 optics. Intense mono‐energetic electron beams have been produced in the energy range of 30 to 150 MeV by controlling plasma length and density precisely. Images of Thomson scattering and fluorescence side scattering from plasma indicate highly relativistic effects such as a long self‐channeling and filamentation as well as energetic electron deflection and intense backward Raman scattering. Preliminary results of the first laser‐plasma accelerator experiment in the range of 200TW femto second pulses are presented.

Objective. To investigate the effect of simulated weightlessness on proliferation of spleen lymphocyte, production of interleukin-2 and expression of c-fos proto-oncogene in mice. Method. Mice were tail-suspended for 7 or 14 days to simulate the effect of weightlessness; proliferation of lymphocyte was measured by MTT method, production of IL-2 was determined by biological activity and expression of c-fos proto-oncogene was determined by dot blotting. Result. As compared with the control, the proliferation of spleen lymphocyte and the production of IL-2 were significantly decreased in 14 d suspended group, but the expression of c-fos proto-oncogene [correction of oncogen] was increased in both 7 d and 14 d suspended groups. Conclusion. This result suggested that simulated weightlessness could interfere with the genes regulating the lymphocyte.

Objective. To observe the protective effects of two kinds of Chinese herb-compounds (Dan-huang-ci compound and Shen-chuan-shu compound) on cellular immunology in tail-suspended rats. Method. The rats were divided into: 1) normal control group; 2) tail-suspended group; 3) tail-suspended + Dan-huang-ci compound; and 4) tail-suspended + Shen-chuan-shu compound. Ability of lymphocyte proliferation and production of IL-2 in rats in the four groups were compared after 21 d. Result. The immunological function of tail-suspended control group decreased significantly as compared with normal control group. Shen-chuan-shu compound could improve immunological function of tail-suspended rats obviously. Conclusion. Shen-chuan-shu compound could enhance cellular immunological function in rats under simulated weightlessness.

To observe the effect of -6 degrees head-down bed-rest on proliferation of lymphocyte and production of certain cytokines.6 healthy young men served as the subjects. Peripheral blood lymphocyte was assayed 1d prior to and on the 3rd day and 6th day of bed rest.The production of IFN-alpha on the 3rd day was markedly decreased (P0.05), but killing activity of NK was significantly enhanced (P0.05), production of IFN-gamma and expression of IL-2 receptor were all slightly reduced. Both production of IFN-alpha and killing activity of NK resumed to the control level on the 6th day, production of IFN-r and CD25 were significantly lowered (P0.05) on the 6th day, a lymphocyte proliferation and production of IL-2 were gradually decreased with time, but production of IL-6 was gradually increased.-6 degrees head-down bed-rested has certain effect on cellular immune function in man.

To observe the effects of simulated weightlessness on the immunogenic activities in mice.T cell subpopulations and the activity of IL-2 and IL-6 were observed in mice after exposure to head-down (-30 degrees) tail suspension for 3 d and 7 d.The activity of IL-2 and IL-6 in mice showed no change after simulated weightlessness for 3 d compared with the control group. But after simulated weightlessness for 7 d, CD3+ and CD4+ were markedly reduced (both P0.01) and CD8+ and CD4+/CD8+ also tended to decrease; the activity of IL-2 was significantly decreased, while the activity of IL-6 tended to increase.Simulated weightlessness for 7 d had significant effects on T cell subpopulations and the activity of certain cytokines in mice.

To investigate the effect of simulated weightlessness on apoptosis of thymus cells in mice.Tail-suspended mice were used as an animal model of simulated weightlessness; chromosome breakage was measured by PI staining, and changes of cell membrane were determined by Annexin-V analysis.As compared with the control, there was no obvious chromosome breakage; the total number of apoptotic cells and number of early apoptotic cells increased in 1 d suspended group; the number of early apoptotic cells increased significantly and the total number of apoptotic cells increased very significantly in 2d suspended groups.These results suggested that simulated weightlessness could promote apoptosis of thymus cells.

GABA is formed primarily from decarboxylation of glutamate by a family of cytosolic and membrane-bound GAD enzymes. In the adult, GAD-derived GABA sustains the vitality of the central nervous system (CNS), since blockage of GAD rapidly leads to convulsions and death. In plants, cytosolic GAD synthesizes GABA in response to hormones and environmental stress. Since decarboxylation involves protonation, secretion of GABA serves to buffer cytosolic pH in plant cells. Families of GAD and GABAA receptor/Cl- channel transcripts and encoded proteins emerge early and seemingly everywhere during CNS development, with their abundance closely paralleling neurogenesis and peaking before birth. Micromolar GABA acts at receptor/Cl-channels to depolarize progenitor cells in the cortical neuroepithelium; it also elevates their cytosolic Ca2+ (Cac2+) levels. In some way, these effects decrease proliferation. GABA directs the migration of postmitotic neuroblasts at femtomolar concentrations and stimulates their random motility at micromolar concentrations via Ca2+ signaling mechanisms. Activation of GABAA receptors by micromolar GABA may limit motility via membrane depolarization and elevated Cac2+. These results indicate that in vitro GABA can affect embryogenesis of the CNS through effects on cell proliferation and migration. As neurons differentiate postnatally, Cl(-)-dependent depolarization disappears together with GABAergic Cac2+ signals. Physiologically occurring GABAergic signals at Cl-channels exist in tonic and transient forms. Since the former are found on progenitor cells while both are present in postmitotic neurons, mechanisms to generate transients differentiate in the latter. Surprisingly, tonic and transient forms of GABAergic signaling at Cl-channels are rapidly and smoothly interconvertible and seem to be derived from online GABA synthesis in a surface-accessible compartment of the membrane.

Cerebral spinal fluid (CSF) pulse waveform basing on 899 records was classified. Eleven types of CSF pulse waveform were further classified according to the harmonic wave relation and the configuration of the pulse waveform. The characteristic features of various types of CSF pulse waveform were considered to reflect certain intracranial pathophysiological conditions including cerebral compliance, cerebral vasomotor reactivity and intracranial elastance.

Synthetic corticotropin-releasing factor (CRF) was administered pre-operatively to five patients who underwent craniotomy for brain tumors, acute subdural and intracerebral hematomas. After craniotomy, an intraventricular catheter is placed in the ventricle, on the normal side of brain. This is for intracranial pressure monitoring. The data obtained were pooled and compared with the saline group (n = 6). The CRF group was found to have statistically significant difference (P less than 0.01). This preliminary study showed that CRF decreases postoperative edema.

Light and proton emission from rear surface of sandwich-like targets, which are irradiated by intense femtosecond laser pulses, have been measured. It is found that both of them depend on the transport material and density inside the targets. For metal transport layers the patterns of the optical images and the proton beams are uniform. While for the transport layers of dielectric, low-density foam and vacuum gap, the patterns are broken up. This indicates that the fast electron beams are also broken up probably due to instabilities.

Experiments were carried out on mice and the subjects irradiated for cancer therapy to evaluate the protective efficacy of a Chinese medicinal herb-compound (CMHC). The lethality and the degree of leucopenia caused by radiation in mice medicated with CMHC were significantly less in comparison with control mice (p less than 0.01 and p less than 0.001, respectively). CMHC significantly improved the WBC and the thrombocytes in irradiated workers (p less than 0.01 and p less than 0.001, respectively). The WBC count of 40 patients under radiotherapy while treated with CMHC recovered from 3450 +/- 77/c.mm to 5425 +/- 264/c.mm (p less than 0.001); whereas, in the control group, without any medication, the WBC count dropped significantly (p less than 0.001). Our results revealed the applicabilities of CMHC in protection against radiation damage in spaceflight and in other fields.

The characteristics of proton beam generated in the interaction of an ultrashort laser pulse with a large prepulse with solid foils are experimentally investigated. It is found that the proton beam emitted from the rear surface is not well collimated, and a “ring-like” structure with some “burst-like” angular modulation is presented in the spatial distribution. The divergence of the proton beam reduces significantly when the laser intensity is decreased. The “burst-like” modulation gradually fades out for the thicker target. It is believed that the large divergence angle and the modulated ring structure are caused by the shock wave induced by the large laser prepulse. A one-dimensional hydrodynamic code, MED103, is used to simulate the behavior of the shock wave produced by the prepulse. The simulation indicates that the rear surface of the foil target is significantly modified by the shock wave, consequently resulting in the experimental observations.

Adrenocortical carcinoma tissue removed from a mildly hirsute 16-year-old girl was cultured in order to assess steroidogenesis and responsiveness of the cells to adrenocorticotropic hormone (ACTH), human chorionic gonadotropin (HCG), and insulin. The cells in culture produced large amounts of androstenedione and testosterone; however, production of cortisol, which was initially high, decreased with time. No aldosterone, estrone, or estradiol was produced in vitro. Both monolayer cells maintained for 6 weeks and organ culture explants maintained for over 3 days responded to ACTH (10(-7) M) with increased production of androgens (testosterone, androstenedione, dehydroepiandrosterone) but decreased production of cortisol as measured by radioimmunoassay of steroids in the culture media. Concomitant with decreased cortisol production was the enhanced formation of 11-deoxycortisol in cells exposed to ACTH, suggesting impaired 11 beta-hydroxylation. Tissue exposed to HCG (10(-7) M) in organ culture showed an increase in androgen production over control levels, but no significant effect of HCG on glucocorticoid production was found. Tumor cells differed in their androgen response to ACTH and HCG, with enhanced adrenal androgens in the presence of ACTH and more gonadal-type androgens after exposure to HCG. Insulin exposure had no effect on production of either androgen or glucocorticoid by tumor tissue in organ culture. Thus, this adrenocortical carcinoma showed marked androgen production in culture which was enhanced in different ways by ACTH and HCG. 11 beta-Hydroxylation was impaired with time in culture. No specific effect of insulin on steroidogenesis was noted.