[Legal regulation of clinical application of artificial intelligence]

With the wide application of artificial intelligence (AI) technology in clinical practice, more and more legal problems need to be solved. At present, although the legal status of AI is still controversial in academic and practical circles, its infringement risk in clinical diagnosis and surgery cannot be avoided. On the basis of the distinction between strong and weak AI liability subjects, those who meet the requirements of infringement, damage consequence, causal relationship, subjective fault, etc., can constitute tort liability, but the existence of exemption causes can also exempt liability. In addition to the ex post accountability of tort liability, it is also necessary to establish a complete administrative legal regulation system. At present, China needs to explore and establish the classification registration system, compulsory insurance system and reserve system of AI as soon as possible, so as to strengthen the legal regulation of the whole process of AI clinical application before, during and after the event.

Formation and evolution of carbonaceous asteroid Ryugu: Direct evidence from returned samples

Samples of the carbonaceous asteroid Ryugu were brought to Earth by the Hayabusa2 spacecraft. We analyzed 17 Ryugu samples measuring 1 to 8 millimeters. Carbon dioxide-bearing water inclusions are present within a pyrrhotite crystal, indicating that Ryugu's parent asteroid formed in the outer Solar System. The samples contain low abundances of materials that formed at high temperatures, such as chondrules and calcium- and aluminum-rich inclusions. The samples are rich in phyllosilicates and carbonates, which formed through aqueous alteration reactions at low temperature, high pH, and water/rock ratios of <1 (by mass). Less altered fragments contain olivine, pyroxene, amorphous silicates, calcite, and phosphide. Numerical simulations, based on the mineralogical and physical properties of the samples, indicate that Ryugu's parent body formed ~2 million years after the beginning of Solar System formation.

Incubation determines favorable microbial communities in Chinese alligator nests

Nest materials are a major heat source due to rotting promoted by microbial activity. Additionally, they are a potential microbial source given their direct contact with eggshells. Microbial dynamics during incubation have been studied in wild birds; however, similar studies in reptiles remain elusive. Here, the study characterized microbial communities in the nest materials of Chinese alligator (Alligator sinensis) using high-throughput sequencing of bacterial 16S rRNA genes and fungal internal transcribed spacer (ITS) region sequences. The results showed that significant changes in the diversity and structure of microbial communities according to different incubation periods. The diversity and richness of bacterial species increased significantly over time, but the relative abundance of the most dominant bacteria in pre-incubation period, including some pathogenic bacteria, declined after incubation. In contrast, fungal species diversity and richness decreased significantly with time. Additionally, nest material composition significantly influenced microbial community structure rather than species diversity and richness. Notably, the fungal community structure showed a stronger response than bacteria to nest material composition, which varied due to differences in plant litter composition. Our results demonstrate the significant response of microbial community diversity and structure to differences in incubation periods and nest material composition in reptiles. It is further emphasized that the importance of incubation period in the conservation of the Chinese alligator and could inform similar studies in other reptiles and birds.

[Analysis of prognostic factors of pediatric kidney transplantation]

Objective: To evaluate the short-and mid-term efficacy of pediatric kidney transplantation and the risk factors for kidney graft and recipient. Methods: The baseline data and postoperative complications of pediatric donors and recipients of 284 kidney transplants were retrospectively analyzed in the Department of Kidney Transplantation in the First Affiliated Hospital of Zhengzhou University from August 2010 to May 2021 and all subjects were followed up until December 31, 2021. According to the survival status of donors and recipients, they were divided into the graft-loss group and the graft-survival group, and the recipient death group and survival group, respectively. Univariate comparison between groups was performed by Log-rank test, and Cox proportional risk model was used to explore the independent risk factors for the graft and recipient survival. Results: Among the 284 children recipients, 184 cases (64.8%) were male and 100 cases(35.2%) were female, and 19 cases (6.7%) were living relative donor renal transplantation, 19 cases (6.7%) were preemptive transplantation, and 8 cases were secondary transplantation. The age of 284 recipients at the time of transplantation was 13.0 (9.0, 15.0) years, among whom 29 cases aged 0-6 years, 96 cases aged 7-11 years old, and 159 cases aged 12-18 years. The 1, 3, and 5 year survival rates were 92.3%, 88.9% and 84.8% for the kidney grafts, and were 97.1%, 95.6% and 94.4% for the recipients, respectively. Multivariate analysis showed postoperative acute rejection (HR=3.14, 95%CI 1.38-7.15, P=0.006) and perioperative vascular complications (HR=4.73, 95%CI 2.03-11.06, P<0.001) were independent risk factors for the survival of kidney graft. Postoperative infection (HR=14.23, 95%CI 3.45-58.72, P<0.001) was an independent risk factor for the postoperative mortality of recipients. Conclusions: Pediatric kidney transplantation shows a good short-and mid-term prognosis. Postoperative acute rejection and perioperative vascular complications are the risk factors for the survival of kidney graft, and postoperative infection is the risk factor affecting the survival of recipient.

Sex-Biased miRNAs in the Gonads of Adult Chinese Alligator (Alligator sinensis) and Their Potential Roles in Sex Maintenance

MicroRNA (miRNA) is a category of single-stranded non-coding small RNA (sRNA) that regulates gene expression by targeting mRNA. It plays a key role in the temperature-dependent sex determination of Chinese alligator (Alligator sinensis), a reptile whose sex is determined solely by the temperature during the incubation period and remains stable thereafter. However, the potential function of miRNAs in the gonads of adult Chinese alligators is still unclear. Here, we prepared and sequenced sRNA libraries of adult female and male alligator gonads, from breeding (in summer) and hibernating (in winter) animals. We obtained 130 conserved miRNAs and 683 novel miRNAs, which were assessed for sex bias in summer and winter; a total of 65 miRNAs that maintained sex bias in both seasons were identified. A regulatory network of sex-biased miRNAs and genes was constructed. Sex-biased miRNAs targeted multiple genes in the meiosis pathway of adult Chinese alligator oocytes and the antagonistic gonadal function maintenance pathway, such as MOS, MYT1, DMRT1, and GDF9. Our study emphasizes the function of miRNA in the epigenetic mechanisms of sex maintenance in crocodilians.

Toxicokinetics of mono-(2-ethylhexyl) phthalate with low-dose exposure applying fluorescence tracing technique

Di(2-ethylhexyl) phthalate (DEHP) belongs to environmental endocrine disrupting chemicals (EEDCs) and can be rapidly hydrolyzed into the ultimate toxicant mono-2-ethylhexyl phthalate (MEHP). In this study, we used 5-aminofluorescein modified MEHP (MEHP-AF) as a fluorescence tracer to explore the toxicokinetics, including toxicokinetic parameters, absorption and transport across the intestinal mucosal barrier, distribution and pathological changes of organs. While the dose was as lower than 10 mg/kg by intragastric administration, the toxicokinetic parameters obtained by fluorescence microplate method were similar to those with the literatures by chromatography. MEHP-AF can be rapidly absorbed through the intestinal mucosal barrier in rats. In situ organ distribution in mice showed that MEHP-AF was mainly concentrated in the liver, kidney and testis. Our results suggested that the fluorescence tracing technique had the advantages with easy processing, less time-consuming, higher sensitivity for the quantitative determination, In addition, this technology also avoids the interference of exogenous or endogenous DEHP and MEHP in the experimental system. It also can be utilized to the visualization detection of MEHP in situ localization in the absorption organ and the toxic target organ. The results show that this may be a more feasible MEHP toxicological research method.

Oral administration co-delivery nanoparticles of docetaxel and bevacizumab for improving intestinal absorption and enhancing anticancer activity

In this study, to improve the intestinal absorption of small molecule chemotherapeutic drug docetaxel (DTX) and macromolecular monoclonal antibody drug bevacizumab (BVZ), we designed and prepared a type of co-delivery nanoparticles for the oral administration of DTX and BVZ. Carboxymethyl chitosan (CMC) and poly(lactic-co-glycolic acid) (PLGA) were used as the carrier of DTX nanoparticles (CPNP_DTX), and methoxy polyethylene glycol-poly (β-amino ester) (mPEG-PAE) was used as the carrier of BVZ nanoparticles (PPNP_BVZ). Then, the two nanoparticles were physically mixed in mass ratios to form mixed co-delivery nanoparticles, which was named as CPNP_DTX&PPNP_BVZ. The nanoparticles were characterized with pH-sensitive drug release property. CPNP_DTX&PPNP_BVZ could significantly increase the bioavailability of DTX and BVZ according to the more cellular uptake in Caco-2 cells and the higher absorption in the intestinal tissue. Compared with free DTX and BVZ, CPNP_DTX&PPNP_BVZ showed excellent cytotoxic effects on A549 cells. Our study revealed the potential of co-delivery nanoparticles of binary mixture of chemotherapeutic small molecule and macromolecular antibody drug as an oral administration therapeutic system.

Food emulsifier polysorbate 80 promotes the intestinal absorption of mono-2-ethylhexyl phthalate by disturbing intestinal barrier

Di-2-ethylhexyl phosphate (DEHP) and its main toxic metabolite mono-2-ethylhexyl phthalate (MEHP) are the typical endocrine disrupting chemicals (EDCs) and widely affect human health. Our previous research reported that synthetic nonionic dietary emulsifier polysorbate 80 (P80, E433) had the promotional effect on the oral absorption of DEHP in rats. The aim of this study was to explore its mechanism of promoting oral absorption, focusing on the mucus barrier and mucosal barrier of the small intestine. A small molecule fluorescent probe 5-aminofluorescein-MEHP (MEHP-AF) was used as a tracker of MEHP in vivo and in vitro. First of all, we verified that P80 promoted the bioavailability of MEHP-AF in the long-term and low-dose exposure of MEHP-AF with P80 as a result of increasing the intestinal absorption of MEHP-AF. Afterwards, experimental results from Western blot, qPCR, immunohistochemistry, and immunofluorescence showed that P80 decreased the expression of proteins (mucus protein mucin-2, tight junction proteins claudin-1 and occludin) related to mucus barrier and mucosal barrier in the intestine, changed the integrity of intestinal epithelial cell, and increased the permeability of intestinal epithelial mucosa. These results indicated that P80 promoted the oral absorption of MEHP-AF by altering the intestinal mucus barrier and mucosal barrier. These findings are of great importance for assessing the safety risks of some food emulsifiers and clarifying the absorption mechanism of chemical pollutants in food, especially for EDCs.

Heating events in the nascent solar system recorded by rare earth element isotopic fractionation in refractory inclusions

Equilibrium condensation of solar gas is often invoked to explain the abundance of refractory elements in planets and meteorites. This is partly motivated, by the observation that the depletions in both the least and most refractory rare earth elements (REEs) in meteoritic group II calcium-aluminum-rich inclusions (CAIs) can be reproduced by thermodynamic models of solar nebula condensation. We measured the isotopic compositions of Ce, Nd, Sm, Eu, Gd, Dy, Er, and Yb in eight CAIs to test this scenario. Contrary to expectation for equilibrium condensation, we find light isotope enrichment for the most refractory REEs and more subdued isotopic variations for the least refractory REEs. This suggests that group II CAIs formed by a two-stage process involving fast evaporation of preexisting materials, followed by near-equilibrium recondensation. The calculated time scales are consistent with heating in events akin to FU Orionis- or EX Lupi-type outbursts of eruptive pre-main-sequence stars.

[The proatherogenic effect of high salt diet combined with focal hypoperfusion on spontaneous hypertension rat]

Objective: To explore the histopathology, monocytes phenotypes and brain mRNA transcription of angiogenic and atherogenic factors preliminarily in spontaneous hypertensive rats (SHRs) fed with high salt diet and subjected to chronic focal hypoperfusion. Methods: A total of 21 SHRs were randomly assigned into SHR with normal diet (SHR-ND group, n=7), SHR fed with high salt (8%) chows (SHR-HSD group, n=14) groups. After induction of high salt diet for 20 weeks, unilateral carotid artery occlusion was applied to one half of SHR-HSD (SHR-HSD-UCAO, n=7) group for 10 weeks to mimic chronic focal cerebral hypoperfusion. The neuropathology, monocytes phenotypes and brain transcription of fibroblast growth factor (FGF-b), platelet-derived endothelial cell growth factor (PD-ECGF), angiogenin (ANG), transforming growth factor-β (TGF-β) and vascular endothelial growth factor A (VEGF-A) among three groups were compared. Results: The systolic blood pressure ((246±12) mmHg vs (220±16) mmHg, P=0.0291, 1 mmHg=0.133 kPa) and diastolic blood pressure ((189±15) mmHg vs (164±12) mmHg, P=0.0143) of SHR-HSD group were elevated significantly compared with those of SHR-ND group. Compared with normotensive Wistar-Kyoto (WKY), SHR-ND, SHR-HSD and SHR-HSD-UCAO groups demonstrated lipohyalinosis, vessel wall thickening, lumen narrowing and multiple enlarged perivascular space and diffuse disarrangement of nerve fiber and myelin vacuolation in corpus callosum pathologically. The ratio of CD11b(+) CD68(+) monocytes in peripheral blood of SHR-HSD group was higher compared with both SHR-ND and SHR-HSD-UCAO groups (P=0.000 8). The mean inflorescence index (MFI) of CD86 and CD206 showd considerable decline in SHR-HSD-UCAO group compared with those of SHR-HSD group (P=0.018 7 and 0.016 8, respectively). The CD86 MFI of CD11b+CD68+ monocytes in SHR-HSD-UCAO group was remarkably higher than that of SHR-ND and SHR-HSD groups (P=0.000 5). Compared with SHR-ND and SHR-HSD groups, the brain mRNA transcription of angiogenic factors including PD-ECGF and ANG were down-regulated (P=0.004 6 and 0.000 2, respectively), while the atherogenic factors including TGF-β and VEGF-A were up-regulated in SHR-HSD-UCAO group (P<0.000 1 and P=0.045, respectively). Conclusion: SHR-HSD-UCAO group shares the pathophysiological characteristics with advanced stage arteriosclerotic cerebral small vessel disease (aCSVD), including neuropathology, imbalanced circulating monocytes phenotypes and down-regulated angiogenic factors.

Circular RNAs in liver diseases: Mechanisms and therapeutic targets

Circular RNAs (circRNAs) are formed from the genome through diverse back splicing and feature the closed loop. circRNAs are widely available in a variety of cells and characterized by conservation, structural stability, high abundance and tissue-specific or developmental-specific expression. Recent studies have shown that circRNAs are closely related to liver diseases, such as metabolic-associated fatty liver disease, hepatitis, liver cirrhosis and hepatocellular carcinoma. circRNAs play an important role in the progression of liver diseases, are potential diagnostic and prognostic markers, and have translational value in therapy. This article reviews the research on circRNAs in liver diseases, with a view to providing a theoretical basis and new ideas for future research and treatment of liver diseases.

In Situ Fluorescence Tracking Toxic Metabolite Mono-2-ethylhexyl phthalate (MEHP) of Di-(2-ethylhexyl) phthalate (DEHP) in HeLa Cells

In this study, we synthesized a small molecule fluorescent probe for detecting mono-2-ethylhexyl phthalate (MEHP) named MEHP-AF, which formed by MEHP cross-linked with 5-aminofluorescein (5-AF) through amide bond. MEHP-AF had been purified based on the different physicochemical properties of 5-AF with MEHP. MEHP-AF showed fluorescence characteristics coming from 5-AF and liposoluble property coming from MEHP. After physicochemical characterization, a series of biological studies of its action in cells were carried out. The results indicated that MEHP-AF was a fluorescent probe with strong specificity and high sensitivity. It can visibly track the location of MEHP in HeLa cell or subcellular levels under confocal laser scanning microscopy in situ. This novel fluorescent probe is expected to use for studying its intracellular behavior at the cell level, especially for investigating the interaction between MEHP and cellular molecules.

KrasG12D-LOH promotes malignant biological behavior and energy metabolism of pancreatic ductal adenocarcinoma cells through the mTOR signaling pathway

Oncogenic Kras with loss of heterozygosity (LOH) is frequently detected in various tumours. However, the exact function and mechanism by which KrasG12D-LOH operates remain unclear. Therefore, the current study investigated the effect of KrasG12D-LOH on the malignant phenotype of pancreatic ductal adenocarcinoma (PDAC) cells. Our investigation revealed that KrasG12D-LOH is associated with increased proliferation, invasion and reduced apoptosis in PDAC cells. The results also exhibited enhanced glycolytic phenotype of KrasG12D-LOH PDAC cells. Hyperactive mTOR plays a significant role in the initiation and maintenance of tumors. To investigate the correlation between KrasG12D-LOH and mTOR, the mTOR signaling pathway was detected by western blot analysis. We found that KrasG12D-LOH up-regulated Akt, AMPK, REDD1 and mTOR in PDAC cells. In summary, our results demonstrated that KrasG12D-LOH promotes oncogenic Kras-induced PDAC by regulating energy metabolism and mTOR signaling pathway. These data may provide novel therapeutic perspectives for PDAC.

[Clinical and pathological features and mutational types of WT1 mutation-associated nephropathy]

Objective: To explore the clinical and pathological features and mutational types and their relations with WT1 mutation-associated nephropathy (WT1MAN). Methods: The clinical and pathological data and the results of WT1 mutation analysis of the cases from Nanfang Hospital of Southern Medical University, Sun Yat-sen Memorial Hospital and The First Affiliated Hospital of Sun Yat-sen University whom we recruited recently and reported during the last ten years were analyzed. Results: Totally, 20 cases (6 males and 14 females), included 5 newly diagnosed cases, were recruited. (1) Ten children were diagnosed with Denys-Drash syndrome (DDS): The median onset age of proteinuria was 1 year and 7 months. Diffuse mesangial sclerosis (DMS) were revealed in 3 cases, minimal lesions (MCD) in 4 cases, and focal segmental glomerulosclerosis (FSGS) in 1 case; renal pathology was not available in the other 2 cases. Glomerular basement membrane (GBM) thickening was observed in 2 cases. Calcineurin inhibitors (CNIs) were administered in 5 cases, complete remission of proteinuria was observed in 3 cases, partial remission in the other 2 cases. Genetic analysis revealed that six cases had WT1 missense mutation, 3 had nonsense mutation, and 1 had frameshift mutation. (2) Two cases were diagnosed with Frasier syndrome (FS): proteinuria was observed at 1 year and 1 month of age and 1 year and 9 months of age, respectively. FSGS with GBM layering were observed in both cases. They progressed to ESRD at 1 year and 6 months of age and 6 years and 6 months of age, respectively. CNI was tried in 1 case with partial proteinuria remission. Both patients were detected to have WT1 splice mutation. (3) Isolated nephropathy (IN) was observed in 8 cases: three had splice mutation, 5 had missense mutation. Of the 3 patients with splice mutation, one was found to have nephropathy and renal failure at the age of 5 months. The other two cases (1 was FSGS and another MCD), both had GBM layering. CNIs were tried on both of them, one got partial remission with normal renal function at the age of fourteen years, the other one had no response and entered ESRD at the age of 6 years and 9 months. Of the 5 cases with missense mutation, 3 had DMS, 2 of them entered ESRD within 6 months of age, another case had DMS entered ESRD at 9 years of age. One case with FSGS, was treated with CNIs and got complete remission. Conclusions: Slow progression (7/10) nephropathy was observed in DDS patients. Missense mutation (11/20) was the most common type of WT1 variants, followed by splice mutation (5/20) in this group of patients. Early onset nephropathy (4/5), rapid progression (4/5) and GBM layering (4/4) wereobserved in patients with splice mutation. CNI was effective in reducing or even eliminating proteinuria in WT1 MAN patients (8/9).

A compact membrane-driven diamond anvil cell and cryostat system for nuclear resonant scattering at high pressure and low temperature

A new miniature panoramic diamond anvil cell (mini-pDAC) as well as a unique gas membrane-driven mechanism is developed and implemented to measure electronic, magnetic, vibrational, and thermodynamic properties of materials using the nuclear resonant inelastic X-ray scattering (NRIXS) and the synchrotron Mössbauer spectroscopy (SMS) simultaneously at high pressure (over Mbar) and low temperature (T < 10 K). The gas membrane system allows in situ pressure tuning of the mini-pDAC at low temperature. The mini-pDAC fits into a specially designed compact liquid helium flow cryostat system to achieve low temperatures, where liquid helium flows through the holder of the mini-pDAC to cool the sample more efficiently. The system has achieved sample temperatures as low as 9 K. Using the membrane, sample pressures of up to 1.4 Mbar have been generated from this mini-pDAC. The instrument has been routinely used at 3-ID, Advanced Photon Source, for NRIXS and SMS studies. The same instrument can easily be used for other X-ray techniques, such as X-ray radial diffraction, X-ray Raman scattering, X-ray emission spectroscopy, and X-ray inelastic scattering under high pressure and low temperature. In this paper, technical details of the mini-pDAC, membrane engaging mechanism, and the cryostat system are described, and some experimental results are discussed.

Bandwidth correction in the spectral measurement of light-emitting diodes

Light-emitting diodes (LEDs) are widely employed in industrial applications and scientific research. However, spectral distortions will occur due to the broadening effects of the spectrometer when an LED spectrum is obtained with a spectrometer. In this paper, a novel approach is put forward to correct bandwidth for an LED spectrum based on a Levenberg-Marquardt algorithm and He-Zheng model. We compare estimation errors of different LED spectra by using the proposed method along with the Richardson-Lucy method and differential operator approach. The experimental results show that the effect of the proposed approach is better than that of the other two methods.

Vibrational dynamics (IR, Raman, NRVS) and a DFT study of a new antitumor tetranuclearstannoxane cluster, Sn(iv)-oxo-{di-o-vanillin} dimethyl dichloride

The vibrational dynamics of a newly synthesized tetrastannoxane was characterized with a combination of experimental (Raman, IR and tin-based nuclear resonance vibrational spectroscopy) and computational (DFT/B3LYP) methods, with an emphasis on the vibrations of the tin sites. The cytotoxic activity revealed a significant regression selectively against the human pancreatic cell lines.

Importance of CD44 on umbilical cord mesenchymal stem cells for expansion of hematopoietic cells

Human umbilical cord mesenchymal stem cells (hUCMSCs) have important functions on the expansion of hematopoietic stem cells (HSCs) through providing the essential microenvironment for hematopoiesis. In order to test whether CD44 on hUCMSCs could have a key function for the ability of hUCMSCs to expand human HSCs, the soluble anti&mdash;CD44 antibody was added to the co&mdash;cultures of hUCMSCs and cord blood (CB) CD34+ cells, which blocked the ability of hUCMSCs to expand CB CD34+ cells significantly. Long&mdash;term culture initiating cell (LTC&mdash;IC) assay revealed that the ability of multipotent differentiation of CB CD34+ cells co&mdash;cultured with CD44 knockdown hUCMSCs could only retain lasting at most for 5 weeks in vitro. In vivo assay, based on non&mdash;obese diabetic/severe combined immunodeficient disease (NOD/SCID) mice, revealed that the hematopoietic reconstitution potential of CB CD34+ cells co&mdash;cultured with CD44 knockdown hUCMSCs is significantly reduced. The hematopoietic supporting ability of hUCMSCs in vivo and in vitro is reduced upon the knockdown of CD44. CD44 has important functions on the ability of hUCMSCs to expand human HSCs in the cell&mdash; extrinsic control.

Element-resolved thermodynamics of magnetocaloric LaFe(13-x)Si(x)

By combination of two independent approaches, nuclear resonant inelastic x-ray scattering and first-principles calculations in the framework of density functional theory, we demonstrate significant changes in the element-resolved vibrational density of states across the first-order transition from the ferromagnetic low temperature to the paramagnetic high temperature phase of LaFe(13-x)Si(x). These changes originate from the itinerant electron metamagnetism associated with Fe and lead to a pronounced magneto-elastic softening despite the large volume decrease at the transition. The increase in lattice entropy associated with the Fe subsystem is significant and contributes cooperatively with the magnetic and electronic entropy changes to the excellent magneto- and barocaloric properties.

Cloning and functional identification of a novel BCA3 splice

The human breast cancer-associated gene (BCA3) was first discovered in breast and prostate cancer cells lines. In vivo studies have shown that BCA3 is mainly expressed in breast tumor cells and not in normal breast and prostate tissues. To date, 3 splice variants of BCA3 have been reported: a double-absent variant lacking exon 3 and exon 5 (BCA3-1), an exon 3-absent variant (BCA3-2), and full-length BCA3. In this study, we investigated whether a novel BCA3 splice variant exists that lacks only the exon 5-encoding sequence. BCA3 variant splices were subcloned and sequenced using reverse transcription-polymerase chain reaction. The preliminary biological functions of the splices were identified using confocal microscopy and a luciferase assay. The absence of exon 3 and exon 5 influenced the subcellular localization of BCA3 and nuclear factor kappa B (NF-kB)-dependent gene expression. Exon 3 and exon 5 of BCA3 may function together to provide a nuclear localization signal or transport sequence to enter the nucleus, and exon 3 may contain specific sequence(s) or domain(s) that influence the NF-κB signal cascade. The discovery of novel BCA3 splicing indicates a new cancer research area, which may increase the understanding of cancer generation and development.

Microfocusing options for the inelastic X-ray scattering beamline at sector 3 of the Advanced Photon Source

Synchrotron radiation from third-generation high-brilliance storage rings is an ideal source for X-ray microbeams. The aim of this paper is to describe a microfocusing scheme that combines both a toroidal mirror and Kirkpatrick-Baez (KB) mirrors for upgrading the existing optical system for inelastic X-ray scattering experiments at sector 3 of the Advanced Photon Source. SHADOW ray-tracing simulations without considering slope errors of both the toroidal mirror and KB mirrors show that this combination can provide a beam size of 4.5 µm (H) × 0.6 µm (V) (FWHM) at the end of the existing D-station (66 m from the source) with use of full beam transmission of up to 59%, and a beam size of 3.7 µm (H) × 0.46 µm (V) (FWHM) at the front-end of the proposed E-station (68 m from the source) with a transmission of up to 52%. A beam size of about 5 µm (H) × 1 µm (V) can be obtained, which is close to the ideal case, by using high-quality mirrors (with slope errors of less than 0.5 µrad r.m.s.). Considering the slope errors of the existing toroidal and KB mirrors (5 and 2.9 µrad r.m.s., respectively), the beam size grows to about 13.5 µm (H) × 6.3 µm (V) at the end of the D-station and to 12.0 µm (H) × 6.0 µm (V) at the front-end of the proposed E-station. The simulations presented here are compared with the experimental measurements that are significantly larger than the theoretical values even when slope error is included in the simulations. This is because of the experimental set-up that could not yet be optimized.

Resource allocation and extracellular acid-base status in the sea urchin Strongylocentrotus droebachiensis in response to CO₂ induced seawater acidification

Anthropogenic CO(2) emission will lead to an increase in seawater pCO(2) of up to 80-100 Pa (800-1000 μatm) within this century and to an acidification of the oceans. Green sea urchins (Strongylocentrotus droebachiensis) occurring in Kattegat experience seasonal hypercapnic and hypoxic conditions already today. Thus, anthropogenic CO(2) emissions will add up to existing values and will lead to even higher pCO(2) values >200 Pa (>2000 μatm). To estimate the green sea urchins' potential to acclimate to acidified seawater, we calculated an energy budget and determined the extracellular acid base status of adult S. droebachiensis exposed to moderately (102-145 Pa, 1007-1431 μatm) and highly (284-385 Pa, 2800-3800 μatm) elevated seawater pCO(2) for 10 and 45 days. A 45-day exposure to elevated pCO(2) resulted in a shift in energy budgets, leading to reduced somatic and reproductive growth. Metabolic rates were not significantly affected, but ammonium excretion increased in response to elevated pCO(2). This led to decreased O:N ratios. These findings suggest that protein metabolism is possibly enhanced under elevated pCO(2) in order to support ion homeostasis by increasing net acid extrusion. The perivisceral coelomic fluid acid-base status revealed that S. droebachiensis is able to fully (intermediate pCO(2)) or partially (high pCO(2)) compensate extracellular pH (pH(e)) changes by accumulation of bicarbonate (maximum increases 2.5mM), albeit at a slower rate than typically observed in other taxa (10-day duration for full pH(e) compensation). At intermediate pCO(2), sea urchins were able to maintain fully compensated pH(e) for 45 days. Sea urchins from the higher pCO(2) treatment could be divided into two groups following medium-term acclimation: one group of experimental animals (29%) contained remnants of food in their digestive system and maintained partially compensated pH(e) (+2.3mM HCO(3)(-)), while the other group (71%) exhibited an empty digestive system and a severe metabolic acidosis (-0.5 pH units, -2.4mM HCO(3)(-)). There was no difference in mortality between the three pCO(2) treatments. The results of this study suggest that S. droebachiensis occurring in the Kattegat might be pre-adapted to hypercapnia due to natural variability in pCO(2) in its habitat. We show for the first time that some echinoderm species can actively compensate extracellular pH. Seawater pCO(2) values of >200 Pa, which will occur in the Kattegat within this century during seasonal hypoxic events, can possibly only be endured for a short time period of a few weeks. Increases in anthropogenic CO(2) emissions and leakages from potential sub-seabed CO(2) storage (CCS) sites thus impose a threat to the ecologically and economically important species S. droebachiensis.

Absence of magnetism in hcp iron-nickel at 11 K

Synchrotron Mössbauer spectroscopy (SMS) was performed on an hcp-phase alloy of composition Fe92Ni8 at a pressure of 21 GPa and a temperature of 11 K. Density functional theoretical calculations predict antiferromagnetism in both hcp Fe and hcp Fe-Ni. For hcp Fe, these calculations predict no hyperfine magnetic field, consistent with previous experiments. For hcp Fe-Ni, however, substantial hyperfine magnetic fields are predicted, but these were not observed in the SMS spectra. Two possible explanations are suggested. First, small but significant errors in the generalized gradient approximation density functional may lead to an erroneous prediction of magnetic order or of erroneous hyperfine magnetic fields in antiferromagnetic hcp Fe-Ni. Alternately, quantum fluctuations with periods much shorter than the lifetime of the nuclear excited state would prohibit the detection of moments by SMS.

4f delocalization in Gd: inelastic x-ray scattering at ultrahigh pressure

We present resonant inelastic x-ray scattering and x-ray emission spectroscopy results on Gd metal to 113 GPa which suggest Kondo-like aspects in the delocalization of 4f electrons. Analysis of the resonant inelastic x-ray scattering data reveals a prolonged and continuous delocalization with volume throughout the entire pressure range, so that the volume-collapse transition at 59 GPa is only part of the phenomenon. Moreover, the Lgamma1 x-ray emission spectroscopy spectra indicate no apparent change in the bare 4f moment across the collapse, suggesting that Kondo screening is responsible for the expected Pauli-like behavior in magnetic susceptibility.

New cubic phase of Li3N: stability of the N3- ion to 200 GPa

Diamond-anvil cell experiments augmented by first-principles calculations have found a remarkable stability of the N(3-) ion in Li3N to a sixfold volume reduction. A new (gamma) phase is discovered above 40(+/-5) GPa, with an 8% volume collapse and a band gap quadrupling at the transition determined by synchrotron x-ray diffraction and inelastic x-ray scattering. gamma-Li(3)N (Fm3m, Li(3)Bi-like structure) remains stable up to 200 GPa, and calculations do not predict metallization until approximately 8 TPa. The high structural stability, wide band gap, and simple electronic structure make this N(3-) based system analogous to lower valency compounds (MgO, NaCl, Ne), meriting its use as an internal pressure standard.

First-order isostructural Mott transition in highly compressed MnO

We present evidence for an isostructural, first-order Mott transition in MnO at 105+/-5 GPa, based on high-resolution x-ray emission spectroscopy and angle-resolved x-ray diffraction data. The pressure-induced structural and spectral changes provide a coherent picture of MnO phase transitions from paramagnetic B1 to antiferromagnetic distorted B1 at 30 GPa, to paramagnetic B8 at 90 GPa, and to diamagnetic B8 at 105+/-5 GPa. The last is the Mott transition, accompanied by a significant loss of magnetic moment, an approximately 6.6% volume collapse and the insulator-metal transition as demonstrated by recent resistance measurements.

Expression of hepatocyte-like phenotypes in bone marrow stromal cells after HGF induction

Bone marrow comprises heterogeneous cell populations, of which certain progenitors have demonstrated the ability to differentiate into multiple mesenchymal cell lineages. This study demonstrates the bone marrow stromal cells (BMSCs) with intrinsic plasticity to differentiate into hepatocyte-like phenotypes under in vitro induction of hepatocyte growth factor (HGF). BMSCs isolated from rat femurs and tibias were cultured and passaged 3-4 times in the presence of HGF. Cells were harvested on days 0, 10, and 20 and subjected to examination of any hepatocyte characteristics by flow cytometry, RT-PCR, Western blot, and immunocytochemistry. Expression of albumin and alpha-fetoprotein at both mRNA and protein levels was detectable on day 10. By contrast, c-Met mRNA was significantly decreased in BMSC in the course of HGF induction. Here BMSC was shown to differentiate into hepatocyte-like phenotypes given the HGF induction, as an alternative source for adult stem cell transplantation in liver repair.

Nuclear inelastic x-ray scattering of FeO to 48 GPa

The partial density of vibrational states has been measured for Fe in compressed FeO (wüstite) using nuclear resonant inelastic x-ray scattering. Substantial changes have been observed in the overall shape of the density of states close to the magnetic transition around 20 GPa from the paramagnetic (low pressure) to the antiferromagnetic (high pressure) state. The results indicate that strong magnetoelastic coupling in FeO is the driving force behind the changes in the phonon spectrum of FeO. The paper presents the first observation of changes in the density of terahertz acoustic phonon states under magnetic transition at high pressure.

SF/HGF-c-Met autocrine and paracrine promote metastasis of hepatocellular carcinoma

AIM: To explore the role of SF/HGF-Met autocrine and paracrine in met astasis of hepatocellular carcinoma (HCC).

METHODS: SF/HGF and c-met transcri ption and protein expression in HCC were examined by RT-PCR and Western Blot in 4 HCC cell lines, including HepG2, Hep3B, SMMC7721 and MHCC-1, the last cell line had a higher potential of metastasis. sf/hgf cDNA was transfected by the method of Lipofectin into SMMC7721. SF/HGF and c-met antibody were used to stimulate and block SF/HGF-c-met signal transduction. Cell morphology, mobility, and proliferation were respectively compared by microscopic observation, wound healing assay and cell growth curve.

RESULTS: HCC malignancy appeared to be relative to its met-SF/HGF expression. In MHCC-1, c-met expression was much stronger than that in other cell lines with lower potential of metastasis and only SF/HG F autocrine existed in MHCC-1. After sf/hgf cDNA transfection or conditioned medium of MHCC-1 stimulation, SMMC7721 changed into elongated morphology, and the abilities of proliferation (P < 0.05) and mobility increased. Such bio-activity could be blocked by c-met antibody (P < 0.05).

CONCLUSION: The system of SF/HGF-c- met autocrine and paracrine played an important role in development and metastas is potential of HCC. Inhibition of SF/HGF-c-met signal transduction system may reduce the growth and metastasis of HCC.

Crystal monochromator with a resolution beyond 10(8)

Monochromatization with crystal diffraction has been achieved to a resolution (lambda/delta lambda) beyond 10(8). The monchromator is specifically designed for 23.880 keV synchrotron radiation (lambda = 51.9 pm) for applications involving nuclear resonant scattering from 119Sn. The design uses asymmetrically cut silicon (12 12 12) crystal reflections from two single-crystalline monoliths oriented in a dispersive geometry. A transmitted energy bandwidth of 140 +/- 20 mu eV was measured, corresponding to a resolution of 1.7 x 10(8). Methods of improving efficiency, wavelength stability and resolution are discussed.

Phonon density of states of iron up to 153 gigapascals

We report phonon densities of states (DOS) of iron measured by nuclear resonant inelastic x-ray scattering to 153 gigapascals and calculated from ab initio theory. Qualitatively, they are in agreement, but the theory predicts density at higher energies. From the DOS, we derive elastic and thermodynamic parameters of iron, including shear modulus, compressional and shear velocities, heat capacity, entropy, kinetic energy, zero-point energy, and Debye temperature. In comparison to the compressional and shear velocities from the preliminary reference Earth model (PREM) seismic model, our results suggest that Earth's inner core has a mean atomic number equal to or higher than pure iron, which is consistent with an iron-nickel alloy.

Improving follow-up after an abnormal pap smear: results from a quasi-experimental intervention study

The success of cervical cancer control programs depends on regular screening with the Pap smear test and prompt and appropriate treatment of early neoplastic lesions. Recognizing the potentially grave consequences of lack of follow-up for abnormal Pap smears, numerous intervention studies have tested the impact of a variety of strategies to increase return for follow-up. The majority of these studies were evaluated under controlled experimental conditions. Despite the encouraging findings of these trials, the next step in the research continuum requires that the effectiveness of these interventions be demonstrated in real world settings before full implementation is initiated. We report the results of an evaluation study assessing the combined effectiveness of three intervention modalities found effective in prior randomized studies: a tracking follow-up protocol, transportation incentives, and financial incentives. This study used a before-after, nonequivalent control group design to assess the impact of a multifaceted intervention that included a computerized tracking protocol with transportation and financial incentives. The study was implemented at two major hospitals, two comprehensive health centers (CHC), and nine public health centers (PHC) under the jurisdiction of the Los Angeles County Department of Health Services. One hospital, one CHC, and the four PHC located in the catchment area of the CHC were selected as experimental sites. The control sites - one hospital, one CHC, and five PHC - provided usual care. All women with an abnormal Pap smear at the intervention and control sites were included in the study. The study consisted of a 1-year period of baseline data collection (September 1989-August 1990), followed by a 2(1/2)-year intervention period (September 1990-February 1993). During the intervention period, the intervention protocol was implemented at the experimental sites, and the control sites provided usual care. Overall, we found that the rates of receipt of follow-up care were consistent with those found in similar studies. In contrast to results obtained in these prior randomized trials, we did not find strong and consistent evidence for intervention effects. Significant findings emerged only at the CHC and hospital levels and only for selected years. Results underscore the importance of testing interventions in real world conditions before large-scale implementation is initiated. In addition, this study highlights the challenge of detecting intervention effects in large-scale studies because of the greater measurement difficulties in field studies as compared with controlled experiments.

[Determination of ibandronate by high performance ion exchange chromatography]

A method for the determination of Ibandronate by high performance ion exchange chromatography is reported. Ibandronate can form a complex compound with the copper ion added in the mobile phase. The complex can be detected at UV 240 nm. The effects of pH of mobile phase and concentration of methanol to the retention time were studied. Concentration of 10% methanol and pH 2.5 were suitable for the detection in less than 5 min. The flow rate was 1.0 mL/min. The relative standard deviation of peak area was 0.8%. The linear correlation was observed from 300 mg/L to 1,500 mg/L of Ibandronate (r = 0.9989). The lowest detectable concentration of Ibandronate was 6 mg/L. The method is simple, rapid and reproducible.

[Present-conditions of nutritional knowledge of clinical doctors]

Nutritional knowledge of 184 clinical doctors was investigated by questionnaires. The results showed that clinical doctors did not have enough nutritional knowledge to meet the demands of their work. The doctors grasped fundamental nutritional knowledge better than clinical nutritional knowledge (P < 0.01). There was no significant difference between the doctors in different groups with different academic degrees, professional titles, work histories, and departments (P > 0.05). Therefore, we suggest that the class hours of nutrition science can be added, the course of clinical nutrition can be offered in medical university, and the nutritional knowledge of clinical doctors can be improved by conducting nutritional science training course.

Estimating probabilities of diabetes mellitus using neural networks

Classification problems are often encountered in medical diagnosis. This paper presents an introduction to classification theory and shows how artificial neural networks can be used for classification. We also map out a bootstrapped procedure for interval estimation of posterior probabilities. The entire procedure is illustrated using the diabetes mellitus data in Pima Indians.

Performance of a general location model with an ignorable missing-data assumption in a multivariate mental health services study

In a study of the impact of case management teams in a publicly funded mental health programme, mental health patients were interviewed about a variety of outcomes suggestive of successful community adaptation, such as support from family and friends and avoidance of legal problems. Because outcome data were missing for a number of patients, a follow-up study was carried out to obtain this information form previous non-responders whenever possible. Because the data of interest were multivariate and included both continuous and categorical variables, a candidate approach for handling incomplete data in the absence of follow-up data would have been to fit a general location model, presumably with log-linear constraints on cell probabilities to avoid overfitting of the data. Here, we use available follow-up data to investigate the performance of a series of general location models with ignorable non-response. We note some problems with this approach and embed the discussion of this example in a broader consideration of the role of ignorable and non-ignorable models in applied research.

Characterization of the three-compartment gel-entrapment porcine hepatocyte bioartificial liver

A hybrid bioartificial liver device supporting a large mass of cells expressing differentiated hepatocyte metabolic capabilities is necessary for the successful treatment of fulminant hepatic failure. The three-compartment gel-entrapment porcine hepatocyte bioartificial liver was designed to provide "bridge" support to transplantation or until native liver recovery is achieved for patients with acute liver failure. The device is an automated mammalian cell culture system supporting 6-7 x 10(9) porcine hepatocytes entrapped in a collagen matrix and inoculated into the capillary lumen spaces of two 100 kDa molecular mass cut-off hollow fiber bioreactors. Gel contraction recreates a small lumen space within the hollow fiber which allows for the delivery of a nutrient medium. This configuration supported hepatocyte viability and differentiated phenotype as measured by albumin synthesis, ureagenesis, oxygen consumption, and vital dye staining during both cell culture and ex vivo application. The hollow fiber membrane was also shown to isolate the cells from xenogenic immunoglobulin attack. The gel-entrapment bioartificial liver maintained a large mass of functional hepatocytes by providing a three-dimensional cell culture matrix, by delivering basal nutrients through lumen media perfusion, and by preventing rejection of the xenocytes. These features make this device a favorable candidate for the treatment of clinical fulminant hepatic failure.

[Psychological health level and related psychosocial factors of nurses in Changsha]

The study investigated the psychological health level and related psychosocial factors of nurses. Through cluster sampling, 650 clinical nurses, who come from 5 city hospitals in Changsha, were interviewed with the Symptom Check List-90 (SCL-90), The Life Event Scale, Type A Behavior Questionnaire, and The Social Support Rating Scale. The results indicated that subjects' average symptom score and most factor scores of SCL-90 were significantly higher than that of the chinese norm. Somatization, depression, and obsession are common psychological problems of the clinical nurses, and the psychological health level of middle age group was significantly lower than that of other groups. Regression analysis (both single factor and multiple factors) suggested that TH and CH scores on Type A Questionnaire as well as life event score on the life event score were negatively related to psychological health level while social support score was positively related to it. The influences of psychosocial factors on psychological health level of clinical nurses were discussed.

Regulation of cyclin-dependent kinase inhibitor p21(WAF1/Cip1/Sdi1) gene expression in hepatic regeneration

WAF1/Cip1/Sdi1 (p21) is the prototype of a family of proteins that inhibit cyclin-dependent kinases and regulate cell cycle progression in eukaryotic cells. In addition to normal cell cycle progression, p21 is involved in growth suppression mediated by p53 and transforming growth factor beta (TGFbeta), differentiation, and apoptosis. To gain insight into the possible involvement of p21 in liver cell growth, the expression and regulation of the p21 gene was evaluated in rodent models of liver regeneration and specimens of human liver diseases. Little p21 mRNA was detected in normal liver tissue. After growth stimulation in vivo by 70% partial hepatectomy (PH), the p21 transcript was upregulated in a biphasic manner, with enhanced expression during G1 phase and following S phase. The induction of p21 after PH was regulated primarily at the post-transcriptional level and was due to enhanced mRNA stability. Inhibition of protein synthesis with cycloheximide rapidly induced p21 expression, primarily by post-transcriptional stabilization of the transcript. Hepatic p21 mRNA was also induced by dietary protein deprivation in normal mice. Expression of the p21 gene after PH was similar in p53-deficient (p53 -/-) and wild-type mice, but was p53-dependent following protein deprivation. Primary hepatocytes in culture demonstrated increased p21 expression after treatment with hepatocyte growth factor, TGFbeta, and activin A. p21 mRNA was upregulated in human liver diseases, suggesting a possible role in hepatic growth regulation in pathologic states. The present study demonstrates that p21 is regulated by p53-dependent and -independent pathways in the liver, and is influenced by both mitogenic and growth inhibitory stimuli.

Extrahepatic metabolism of 4-methylumbelliferone and lidocaine in the anhepatic rabbit

Extrahepatic drug metabolism was studied in an anhepatic rabbit model. Plasma concentrations of 4-methylumbelliferone (4-MU) and its major metabolites, 4-methylumbelliferyl-O-glucuronide and 4-methyumbelliferyl sulfate, along with lidocaine and its major metabolites, monoethylglycinexylidide and 3-hydroxylidocaine, were measured in sham rabbits (n = 4) and anhepatic rabbits (n = 4) following bolus intravenous administration of each drug. Along with concentration profiles of the drugs and metabolites, pharmacokinetic analyses of 4-MU metabolism and lidocaine metabolism were used to assess the extrahepatic metabolism of these classical substrates. Total body clearance of 4-MU in the anhepatic rabbits was about 50% that of the sham animals. Extensive extrahepatic glucuronidation of 4-MU was revealed by comparing the AUC ratios of 4-methylumbelliferyl-O-glucuronide and 4-MU in anhepatic and sham rabbit groups. Sulfation of 4-MU was reduced significantly in the anhepatic group, although some extrahepatic sulfation was observed. Total body clearance of lidocaine was reduced 3-fold in anhepatic animals. 3-Hydroxylidocaine was only detected in plasma samples from sham animals. These results emphasize the importance of extrahepatic sites in drug metabolism, especially glucuronidation of phenolic compounds such as 4-MU.

Gel-entrapment bioartificial liver therapy in galactosamine hepatitis

A need exists for an effective, safe bioartificial liver to support patients in fulminant hepatic failure (FHF). The purpose of this study was to determine the treatment efficacy of the novel gel-entrapment porcine hepatocyte bioartificial liver (BAL) in a fatal model of canine hepatic failure. FHF was produced in 27- to 30-kg halothane-anesthetized dogs by bolus infusion of the hepatotoxin D-galactosamine (D-Gal). Three groups were studied during the 48-hr experiment: Group D-Gal (n = 5) received galactosamine, 1.0 g/kg, iv at Time O, Group HepBAL (n = 5) received D-Gal followed by continuous hemoperfusion with the BAL device loaded with approximately 6 billion viable pig hepatocytes starting at Time 24 hr, and three dogs served as healthy controls (Group Control) and received no galactosamine. The primary endpoints were survival and coma development. Group D-Gal demonstrated 100% mortality from liver failure by 42 hr, characterized by a progressive rise in liver enzymes, total bilirubin, ammonia, and lactate and associated with coagulopathy, hypoglycemia, coma, and brain death. BAL therapy significantly delayed the onset of coma and improved survival (median 47 hr vs D-Gal median 36 hr). A significant delay in the rise of lactate and ammonia was also noted. BAL therapy prolonged survival and improved both laboratory and clinical markers of fatal liver failure. These data indicate that this BAL may have clinical utility in supporting human liver failure.

Effects of hepatocyte growth factor on viability and biotransformation functions of hepatocytes in gel entrapped and monolayer culture

OBJECTIVES

An extracorporeal bioartificial liver device must maintain viability and differentiated function of hepatocytes cultivated at high cell density. Growth factors, such as hepatocyte growth factor, found in high concentrations in the plasma of patients with fulminant hepatic failure, have the potential to promote hepatocyte dedifferentiation and thus, decrease function. We tested the hypothesis that hepatocyte growth factor would improve viable cell density and decrease biotransformation functions of liver cells in monolayer culture and in hepatocytes entrapped in collagen cylindrical gel "noodles" as found in the extracorporeal bioartificial liver.

DESIGN

In vitro, controlled study.

SETTING

University research laboratory.

SUBJECTS

Adult Sprague Dawley Rats.

INTERVENTIONS

Hepatocytes were harvested by a two-step collagenase technique. Harvested hepatocytes were plated onto type 1 collagen coated plates or entrapped in type 1 collagen cylindrical gels and cultured in different concentrations of hepatocyte growth factor. Interval measurements of 3H-thymidine incorporation, albumin synthesis, biotransformation functions, and viability were made.

MEASUREMENTS AND MAIN RESULTS

In monolayer culture, the addition of hepatocyte growth factor caused a dramatic increase in 3H-thymidine incorporation. This increase was accompanied by a decrease in the appearance of the lidocaine metabolite, monoethyglycinexylidide. Albumin production was unchanged. In cylindrical gel entrapment cultures, hepatocyte growth factor caused a significant increase in 2-day viability but had no effect on the metabolite appearance of lidocaine or 4-methyl umbelliferone or albumin production.

CONCLUSIONS

Hepatocyte growth factor induces dedifferentiation of hepatocytes in monolayer culture. Collagen matrix entrapment appears to abrogate this effect and improve liver cell viability. There may be reciprocal regulation of hepatocyte reproductive and differentiated functions, such as biotransformation, which can be influenced by the entrapment of hepatocytes in an extracellular type 1 collagen matrix.