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The study aimed to evaluate the correlation between self-reported pubertal developmental scale (PDS) and physically assessed Tanner staging by an experienced pediatrician among girls. In a school population-based study in Zhongshan, China, we recruited 1,722 girls in grades 1–3 by a multistage stratified cluster random sampling method. Participants completed self-reported PDS questionnaire prior to physical examination. Breast development was evaluated by a female pediatrician combined with ultrasound examination for overweight/obese girls; pubic hair development was evaluated. Otherwise, we tested follicle-stimulating hormone (FSH) and luteinizing hormone (LH) for some participants. We observed a weak association between Tanner-derived composite stage (TDCS) and puberty category scores (PCS) (τ=0.288, p<0.001) among all girls. There was correlation (τ=0.314, p=0.001) between ultrasound-derived composite stage (UDCS) and PCS among overweight/obese girls. Moreover, among overweight/obese girls, PCS was positively correlated with LH (r=0.265, p=0.008), but not FSH (r=0.155, p=0.123), and when the basal LH value was greater than 0.3 mIU/mL, the proportion of PCS stage ≥2 (9/18) was higher than the proportion of TDCS ≥2 (5/18). As for the determination of pubertal onset, when UDCS was used as the gold standard, the specificity of PCS was 0.86 and positive predictive value was 90.00 %. There was a weak correlation between PCS and TDCS among girls early adolescence. Moreover, among overweight/obese girls, combining hormone values, ultrasonographic stage of breast, and the positive predictive value of PCS, we posit that self-reported PDS might be a more reliable method than TDCS to evaluate pubertal development among overweight/obese girls. [ABSTRACT FROM AUTHOR]

ObjectiveTo investigate Scleroderma cepa poisoning incident on September 4th 2019 in Chuxiong County, Yunnan Province, analyze the causes of the incident and summarize the clinical experience, and to provide reference for the treatment of mushroom poisoning.MethodsData collection, epidemiological investigation, morphological and phylogenetic identification were taken to analyze the poisoning event.ResultsTwo patients complained of abdominal pain, nausea, vomiting, diarrhea with hypotension 0.5-1 h after ingesting the poisonous mushrooms, who were discharged after symptomatic treatment. The mushroom was identified as Scleroderma cepa by morphological and phylogenetic identification.ConclusionThis incident was a mushroom poisoning caused by accidental ingestion of Scleroderma cepa, which was similar to edible Scleroderma yunnanense. As most mushroom poisoning cases were resulted from the consumption of poisonous mushrooms which were very similar to edible mushrooms in morphology, it is recommended not to collect and eat wild mushrooms.

The upstream regulators of microRNAs were rarely reported. Hydroquinone (HQ) is the main metabolite of benzene, one of the important environmental factors contributing to leukemia and lymphoma. In HQ‐induced malignant transformed TK6 (TK6‐HT) cells, the expression of PARP‐1 and miR‐223 were upregulated. When in PARP‐1 silencing TK6‐HT cells, miR‐223 was downregulated and the apoptotic cell number correspondingly increased. In TK6 cells treated with HQ for different terms, the expression of miR‐223 and PARP‐1 were dynamically observed and found to be decreased and increased, respectively. Trichostatin A could increase the expression of miR‐223, then the expression of HDAC1–2 and nuclear factor kappa B were found to be increased, but that of mH2A was decreased. PARP‐1 silencing inhibited the protein expression of H3Ac, mH2A, and H3K27ac. By co‐immunoprecipitation experiment, PARP‐1 and HDAC2 were found to form a regulatory complex. In conclusion, we demonstrated that the upregulation of PARP‐1 mediated activation of acetylation to promote the transcription of miR‐223 possibly via coregulating with HDAC2, an epigenetic regulation mechanism involved in cell malignant transformation resulting from long‐term exposure to HQ, in which course, H3K27ac might be a specific marker for the activation of histone H3, which also gives hints for benzene exposure research. [ABSTRACT FROM AUTHOR]

The genus Dracaena is the main source of dragon's blood, which is a plant resin and has been used as traditional medicine since ancient times in different civilizations. However, the chromosome numbers and karyotypes present in this genus remain poorly understood. In this study, fluorescence in situ hybridization (FISH) using oligonucleotide probes for ribosomal DNAs (5S and 45S rDNA) and telomeric repeats (TTTAGGG)3 was applied to analyze 4 related species: Dracaena terniflora Roxb., Dracaena cambodiana Pierre ex Gagnep., Aizong (Dracaena sp.), and Dracaena cochinchinensis (Lour.) S.C. Chen. In all 4 species, both 5S and 45S rDNA showed hybridization signals in the paracentromeric region of a pair of chromosomes; the sizes of the 45S rDNA signals were larger than those of the 5S rDNA. Importantly, the telomeric repeat signals were located in the telomeric regions of almost all chromosomes. The results indicated that the chromosome number of all 4 Dracaena species is 2n = 40, and the lengths of the mitotic metaphase chromosomes range from 0.99 to 2.98 μm. Our results provide useful cytogenetic information, which will be beneficial to future studies in genome structure of the genus Dracaena. [ABSTRACT FROM AUTHOR]

Objective To explore whether there was an increased secretion of cystatin C (Cys C) in twin pregnancy. Methods Patients with a total of 281 singleton pregnancies (including 38 patients with preeclampsia) and 72 twin pregnancies, as well as 42 patients who were not pregnant, were included in this study. We tested levels of serum Cys C, creatinine, and uric acid, along with the estimated glomerular filtration rate (eGFR), in different groups. Results The levels of serum Cys C in all 3 trimesters for women with twin pregnancy were much higher than those in the corresponding trimesters for women with singleton pregnancy. However, we observed little change in eGFR in the corresponding trimesters. Cys C/eGFR in the second and third trimester of twin pregnancy increased, compared with the corresponding trimesters of women with singleton pregnancy. Levels of serum Cys C were higher in the third trimester in women with twin pregnancy than that in patients with preeclampsia. Also, Cys C/eGFR in the third trimester of twin pregnancy was close to the level observed in patients with preeclampsia. Conclusions Increased secretion of Cys C could contribute to the elevated serum Cys C levels that we observed in twin pregnancy. [ABSTRACT FROM AUTHOR]

Borehole wall would be disturbed during sampling when drilling into gas hydrate‐bearing sediments, thereby changing the reservoir physical characteristics obtained by well logging. It would cause significant errors using such logging data to estimate the reservoir parameters such as hydrate saturation and mechanical properties. In this paper, the theoretical method of combination cavity expansion theory with the time‐average equation to predict the compressional velocity (Vp) of hydrate‐bearing sediment after drilling disturbance were proposed based on the hypothesis that the compaction of hydrate‐bearing sediments only causes the porosity change in sediments. The theoretical derivation process of calculation the porosity change caused by drilling compaction based on both Tresca's yield criteria and Mohr–Coulomb yield criteria were presented in detail. And the influence of drilling compaction on Vp were discussed by theory method developed in this paper and experimental method. Both theory‐based results and experimental results show that the Vp difference caused by drilling compaction is considerable. Drilling compaction would cause the increase in Vp, and the increment increase with the increase of bit weight, and samples with low hydrate concentrations would be more sensitive to bit weight variations. The proposed method is feasible to simplify the influences of complex processes involved in the disturbance of hydrate‐bearing sediments during drilling. Disturbance of the drilled borehole wall were studied theoretically and experimentally. Mathematical model for predicting the Vp of disturbed hydrate‐bearing sediment was established. Study results show that drilling disturbance would cause significant change in Vp. [ABSTRACT FROM AUTHOR]

Abstract Deep-sea microorganism research has become a hot topic in life science, owing to its special value in high pressure and low temperature environment. If not kept the in-situ low temperature and high pressure, it will cause the microorganism to lose its activity and lead to a waste of resources. A freeze-sediments valve presents a promising solution to maintain the low temperature and high pressure in situ, improve the success rate of sampling and shorten the sampling time. A series of experiments were conducted to characterize the freeze-sediments valve, including the sampling time without leakage, adaptation to different sediments and the effect of the length, etc. Most important of all, temperature change of sediments is observed in all experiments. Experimental results indicated that the freeze-sediments valve was formed in 5 min without leakage and the freeze-sediments valve could be applied to different sediments without limitations on sediments type and mineral content. Considering the pressure retaining capacity and formation time of freeze-sediments valve, it was found that the freeze-sediments valve with a length of 60–80 mm has good pressure retaining capacity whose value was 41.3–48.4 Mpa and short formation time which was 5 min. Precooling the sampler could be used to shorten the sampling time in the actual environment application. This sampling technique can play a vital role in maintaining in-situ low temperature at −2 to −4 ° Celsius in all the experiments. According to the tests, the sampling technique based on the freeze-sediments valve had the potential to solve the problem of keeping in-situ temperature, low sampling success rate and long sampling time in the future. [ABSTRACT FROM AUTHOR]

Hydroquinone (HQ), one of the most important metabolites derived from benzene, induces cell cycle arrest and apoptosis. Poly(ADP-ribose) polymerase-1 (PARP-1) participates in various biological processes, including DNA repair and cell cycle regulation. To explore whether PARP-1 regulatory pathway mediated HQ-induced cell cycle arrest and apoptosis, we assessed the effect of PARP-1 suppression on induction of apoptosis analyzed by FACSCalibur flow cytometer in PARP-1 deficientTK6 cells (TK6-shPARP-1). We observed an increase in the fraction of cells in G1 phase by 7.6% and increased apoptosis by 4.5% in PARP-1-deficient TK6 cells (TK6-shPARP-1) compared to those negative control cells (TK6-shNC cells) in response to HQ treatment. Furthermore, HQ might activate the extrinsic pathways of apoptosis via up-regulation of Fas expression, followed by caspase-3 activation, apoptotic body, and sub G1 accumulation. Enhanced p53 expression was observed in TK6-shPARP-1 cells than in TK6-shNC cells after HQ treatment. In contrast, Fas expression was lower in TK6-shPARP-1 cells than in TK6-shNC cells. Therefore, we conclude that HQ may activate apoptotic signals via Fas up-regulation and p53-mediated apoptosis in TK6-shNC cells. The reduction of PARP-1 expression further intensified up-regulation of p53 in TK6-shPARP-1 cells, resulting in an increased G1→S phase cell arrest and apoptosis in TK6-shPARP-1 cells compared to TK6-shNC cells. [ABSTRACT FROM AUTHOR]

Fluidic oscillator made of tungsten carbide, the core component of the fluidic hammer, has a significantly reduced service life under the erosion wear of drilling fluids with solid particles. Polycrystalline diamond composite (PDC) has the potential to solve this issue due to its extremely high hardness and wear resistance benefits. However, few studies on the slurry erosion wear of PDC have been reported. In this paper, a modified slurry erosion experimental device based on submerged abrasive water jets was used to study the erosion resistance of four grades of PDCs with grain sizes of 2–3, 5, 10 and 25 μm respectively. The erosion surface of the damaged PDC was observed by scanning electron microscope (SEM) and the erosive mechanism of the PDC was analyzed. The experimental results showed that PDC had excellent slurry erosion resistance. The erosion rate of PDC was 1/192–1/43 of that of tungsten carbide when the jet velocity was 100 m/s. The erosion rates of PDC increased with the rise of jet velocity, impact angle and erodent particle size. In addition, the erosion performance of debris represented by quartz to PDC is greater than that of weighting agents represented by barite and hematite. Further research also showed that PDC with fine grain has greater erosion resistance than PDC with coarse grain, except PDC2 ~ 3. At a high impact angle, the erosive mechanism was forming the craters due to the crushing of diamond grains and the pits due to the overall pullout of diamond grains, while at a low impact angle, the erosive mechanism was ploughing and forming directional craters. • A modified slurry erosion experimental device was developed. • Diamond grain size has a significant effect on the erosion rate of PDC. • The erosion rate of PDC is affected by fluid parameters and erosion particle properties. • The erosive mechanisms of PDCs were analyzed. [ABSTRACT FROM AUTHOR]

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Less than 60% hydrate-bearing sediment pressure cores can be retrieved by current pressure corers because of sealing failures. This is attributed to the sensitivity of mechanical valves to solid particles and drilling cuttings. In order to improve the pressurized core recovery of natural gas hydrate-bearing sediment coring, a pressure corer based on an ice valve made out of in situ drilling fluid during coring is proposed. A series of preliminary laboratory experiments were conducted to characterize the ice valves proposed for the pressure corer. The ice valves made from the pure drilling fluid (used in the Scientific Drilling Project of Gas Hydrate in the Qilian Mountains) or the drilling fluid contains different mass concentrations and granularity of quartz and kaolin particles. Several ice valves with various lengths were tested for their sustained pressure. Results show that the sustained pressure of the ice valve increases almost linearly with the valve length. An ice valve formed at −30 °C with a nominal diameter of 58 mm and a length of 85 mm can retain a pressure greater than 25 MPa without leakage. The sustained pressure of the ice valve can be adjusted by changing the ice valve length to accommodate different drilling sites. Experiments verified that the ice valves were insensitive to both solid particles and rust. It indicates that the proposed ice-valve-based pressure corer can be a potential solution to increase the recovery of pressurized hydrate-bearing sediment core. [ABSTRACT FROM AUTHOR]

A computational fluid dynamics (CFD) study was conducted to investigate the effect of several important factors on the dust control performance of a down-the-hole (DTH) air hammer drill bit for reverse circulation drilling in mines. It was shown that an increasing number of suction nozzles or inclination angles of suction nozzles was advantageous to improve dust control performance of the drill bit. Lowering the location of suction nozzles in the drill bit body is another way to increase its ability to control dust. There exists a critical diameter of suction nozzles for dust control performance. A series of experimental tests in the laboratory were carried out to validate the results of CFD modelling. It was shown that the CFD simulation results were in good agreement with experimental data. A prototype of the drill bit was built for testing in laboratory experiments. The same prototype was field-tested by drilling vertically downward exploration boreholes in one of the largest Molybdenum Ore Districts in Luanchuan of Henan Province, China. Field test results indicate that the modified drill bit could control drilling dust effectively. No cuttings escaped from the borehole when it was used for downward drilling. The DTH air hammer drill bit has not been tested for drilling a vertically upward hole, and therefore, future studies are required to improve the suction capacity of the drill bit for drilling vertically upward holes. [ABSTRACT FROM PUBLISHER]

Existing numerical simulation studies show that confining pressure has a negative effect on the efficiency of percussion drilling. However, the corresponding systematic experimental studies considering confining pressure have rarely been reported. In this study, single drop weight impact tests were performed on granite samples and the influence of the confining pressure on the crater parameters was analyzed. Besides, the fluorescent approach was adopted to observe the cracks in the damaged samples. The results indicate that confining pressure has a significant adverse effect on rock fragmentation. For instance, the average volume of crater under confining pressure of 20 MPa is 91.5% smaller than that without confining pressure. Meanwhile, the higher the confining pressure, the shorter the cracks. The confining pressure can inhibit the propagation of side cracks around the crater and hinder the expansion of radial cracks to the free surface. Knowing these phenomena and conclusions, we may be able to eliminate or reduce the negative effect of the confining pressure by optimizing the working parameters of the drilling tools and the layout structure of the buttons on the bit. • The dynamic rock fragmentation performance with confining pressure has been systematically studied by experiments. • The influence of the confining pressure on the crater parameters is quantitatively analyzed. • Crack evolution under confining pressure was revealed by the fluorescent approach. • Confining pressure has a significant adverse effect on dynamic rock fragmentation. [ABSTRACT FROM AUTHOR]

The target strata of sandstone-type uranium deposits are usually located in the fragile and loose strata, which makes it difficult to obtain core samples; consequently, a novel ice coring device for loose sandstone-type uranium deposits is proposed to solve this problem. Experiments proved that the artificial sample can replace the natural sample, and the coring method has high reliability. Ensuring the allegro formation of an ice valve with a given cold source is critical for this coring system, and reducing the loss of cold energy with help of insulation layer is one of the methods to speed up the formation of ice valve. Since the diameter of the drill tool is limited by its working scenario, the thickness of insulation layer is limited to ensure the size of core. Therefore, this paper conducted laboratory experiments of the insulation layer with different thicknesses to study the effect of the insulation layer on the formation of the sand–ice valve. Results show that the insulation layer can reduce the loss of cold energy during the freezing process and significantly affect the formation time of the sand–ice valve. When the thickness of the aerogel insulation layer is 2 mm, the freezing time is 44% shorter than that without insulation layer. According to the tests, the novel ice coring device is expected to solve the coring problem in loose sandstone-type uranium deposits. [ABSTRACT FROM AUTHOR]