Realization of a crosstalk-avoided quantum network node using dual-type qubits of the same ion species.

Generating ion-photon entanglement is a crucial step for scalable trapped-ion quantum networks. To avoid the crosstalk on memory qubits carrying quantum information, it is common to use a different ion species for ion-photon entanglement generation such that the scattered photons are far off-resonant for the memory qubits. However, such a dual-species scheme can be subject to inefficient sympathetic cooling due to the mass mismatch of the ions. Here we demonstrate a trapped-ion quantum network node in the dual-type qubit scheme where two types of qubits are encoded in the S and F hyperfine structure levels of 171Yb+ ions. We generate ion photon entanglement for the S-qubit in a typical timescale of hundreds of milliseconds, and verify its small crosstalk on a nearby F-qubit with coherence time above seconds. Our work demonstrates an enabling function of the dual-type qubit scheme for scalable quantum networks.

[The effects of stelleta ganglion resection on heart failure in response to pressure overload].

Objective: To observe the impact and difference of resection of left stellate ganglion (LSG) or right stellate ganglion (RSG) on rats with heart failure. Methods: Thirty male SD rats were divided into 3 groups (n=10 each) by random number table method: control group, LSG group, RSG group. All three groups underwent TAC surgery to establish a pressure-overloaded heart failure model. Then, LSG and RSG were bluntly separated and removed in rats assigned to the LSG group or RSG group by surgery, while rats in the control group underwent sham operation. The changes in blood pressure and heart rate before operation, 30 minutes and 10 weeks after operation were recorded; echocardiography was performed before operation and 10 weeks after operation to detect the thickness of the ventricular septum, left ventricle posterior wall diameter, left ventricular end diastolic diameter, left ventricular end diastolic volume, and calculate the left ventricular fractional shortening and left ventricular ejection fraction. HE staining and Masson staining were performed to observe the degree of myocardial hypertrophy and myocardial fibrosis, and to judge the ventricular remodeling. Results: The heart rates of the three groups of rats were (352.4±4.3), (320.3±4.0) and (297.9±5.9) beats/min, and the blood pressure was (142.8±2.3), (123.4±2.7) and (129.6±2.9) mmHg(1 mmHg=0.133 kPa) at thirty minutes after surgery; the heart rates of the three groups of rats were (352.9±4.0), (321.6±3.4) and (301±4.1) beats/min, and the blood pressure was (145.6±1.9), (124.8±1.7) and (130.4±4.4) mmHg at 10 weeks after surgery. The heart rate and blood pressure in the LSG group and RSG group at 30 min and 10 weeks after surgery were significantly lower than those in the control group; at 10 weeks after surgery, the heart rate in the RSG group was significantly lower than that in the LSG group (P both<0.001). After 10 weeks, rats in the control group developed severe left ventricular dilatation. Degree of left ventricular hypertrophy was significantly reduced in the LSG group and RSG group than in the control group, the thickness of the ventricular septum was (3.2±0.3), (2.5±0.1) and (2.5±0.1) mm; the left ventricular end-diastolic diameters were (7.5±0.3), (5.5±0.3) and (5.7±0.2) mm; the left ventricular end-diastolic volume was (9.5±0.3), (4.5±0.2) and (4.8±0.2) ml; the left ventricular fractional shortening was (21.6±1.3)%, (49.1±3.9)% and (47.4±1.5)%; and the left ventricular ejection fraction was (50.9±2.5)%, (81.9±2.1)% and (80.0±2.3)%, respectively in the control group, LSG group and RSG group. Compared with the control group, the left ventricular posterior wall diameter, left ventricular end-diastolic diameter and left ventricular end-diastolic volume were significantly lower and the left ventricular fractional shortening and left ventricular ejection fraction were significantly higher in the LSG group and RSG group (all P<0.001). 10 weeks after operation, the values of type Ⅰ collagen in the control group, LSG group, and RSG group were (0.354±0.013), (0.211±0.012) and (0.243±0.013), respectively. Ratio of type Ⅰ/Ⅲ collagen was (1.109±0.065), (0.737±0.055) and (0.839±0.075), respectively. Compared with the control group, the ratio of type Ⅰcollagen and ratio of type Ⅰ/Ⅲ collagen were significantly lower in the LSG group and RSG group (P<0.001). Conclusion: Both left and right stellate ganglion resection can similarly reduce ventricular remodeling caused by pressure overload and delay the progression of heart failure in tis TAC rat model.

[Clinical study of FibroTouch and six serological models for assessing the degree of liver fibrosis in patients with chronic hepatitis B].

Objective: To evaluate the using value of FibroTouch and six serological models in detecting the degree of liver fibrosis in patients with chronic hepatitis B, in an attempt to provide reference for accurate diagnosis. Methods: Two hundred and fifty-eight cases with chronic hepatitis B admitted to Xixi Hospital of Hangzhou from September 1, 2015 to September 1, 2017 were selected. All patients underwent liver histopathological examination and FibroTouch measurement to determine liver stiffness (LSM). Serum biochemical parameters were detected and the scoring values of six serological models were calculated. SAS 9.4 statistical software was used for statistical analysis, and the correlation between FibroTouch and the six serological models was analyzed by Spearman correlation. The diagnostic value of FibroTouch and six serological models was analyzed by receiver operating characteristic curve (ROC) based on liver histopathological findings. Results: The median LSM of 258 cases with chronic hepatitis B was 9.4 (6.5-13.8) kPa. In the six serological models, the median value of aspartate transaminase to platelet ratio index (APRI), FIB-4 index, S-index, Forn's index, PRPindex, and FIB-5 were 0.42 (0.28-0.62), 1.27 (0.78-2.03), 0.11 (0.07-0.20), 6.95 (5.89-8.51), 0.000 8 (0.000 6-0.000 9),and 38.59 (36.28-40.97). FibroTouch had positive correlation with APRI, FIB-4, S-index, Forn's index, PRP, fibrosis stage (r= 0.73,P< 0.001) and inflammation grade, and had negative correlation with FIB-5, and both had statistical significance. The area under curve (AUC) of FT-LSM at S≥2, S≥3, S = 4 were 0.89, 0.90 and 0.85, respectively, which was significantly higher than serological models (P< 0.001). The AUC of S-index model at S≥2, S≥3, S = 4 were higher than other five serological models. Conclusion: The diagnostic performance of FibroTouch is significantly better than serological model. S-index model has the best diagnostic performance in the six serological models, and the combination of S-index and FT-LSM may better diagnose the grading of liver fibrosis, and thus can be applied and promoted in clinic.

[Effect of α7nAChR mediated cholinergic anti-inflammatory pathway on inhibition of atrial fibrillation by low-level vagus nerve stimulation].

Objective: To investigate the effect of α7nAChR mediated cholinergic anti-inflammatory pathway on inhibition of atrial fibrillation by low-level vagus nerve stimulation(LL-VNS). Methods: Eighteen beagles were randomized into control group (n=6), LL-VNS group (n=6) and methyllycaconitine (MLA) + LL-VNS group (n=6). All the beagles were subjected to rapid atrial pacing at 800 beats/min for 6 hours.And the effective refractory period (ERP) of atriums and pulmonary veins and induced atrial fibrillation (AF) were measured hourly during non-pacing.After cessation of pacing for 3 hours, the beagles in control group were injected with saline into four ganglionated plexis (GPs), the beagles in LL-VNS group were given LL-VNS and saline injected into four GPs, and the beagles in MLA+ LL-VNS group were injected with MLA into four GPs combined with LL-VNS.And the levels of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and acetylcholine (ACh) in the plasma at baseline condition, 3 h and 6 h were measured.At the end of this experiment, atrial tissues were collected to examine the levels of TNF-α, IL-6, ACh, NF-κBp65 and STAT3 proteins. Results: During the right atrium pacing for the first 3 hours, the ERPs were gradually decreased while AF inducibility were gradually increased in all groups. At the end of this experiment, compared with the control group and MLA+ LL-VNS group, the ERPs in LL-VNS group were increased, and the induced times and duration of AF were significantly decreased. The levels of TNF-α and IL-6 in plasma were all significantly decreased in LL-VNS group and MLA+ LL-VNS group when compared with the control group(pg/ml) [IL-6: (101±6) vs (119±7), P<0.05; (102±5) vs (119±7), P<0.05; TNF-α: (17.8±1.7) vs (22.1±2.0), P<0.05; (17.9±2.2) vs (22.1±2.0), P<0.05]. And the levels of ACh were higher than in the control group(µg/ml)[(151±13) vs (123±10), P<0.05; (145±5) vs (123±10), P<0.05]. After cessation of pacing for 6 hours, compared with the control groupand MLA+ LL-VNS group, the tissue levels of TNF-α and IL-6 were significantly decreased in LL-VNS group (P<0.05). The concentrations of NF-κBp65 proteins in atrial tissues were lower in the LL-VNS group (P<0.05), and the levels of STAT3 proteins in those tissues were higher in the LL-VNS group than in thein the two other groups (P<0.05). Conclusion: LL-VNS could inhibit the atrial electrical remodeling and atrial fibrillation induction; cholinergic anti-inflammatory pathway mediated by α7nAChR may be the important mechanism in vagal nerve regulated AF.

[Preparation of chaperone-antigen peptide vaccine derived from human gastric cancer stem cells and its immune function].

Objective: To explore the method of extracting chaperone antigen peptide complexes from gastric cancer stem cells and its immune function. Methods: Gastric cancer stem cells and gastric cancer cells were screened by low temperature ultrasonic lysis. After salting out and dialysis, the lysate supernatant was processed with SDS-PAGE to analyze the expression of chaperone antigen peptide complexes, and then was separated and purified with CNBr-activated SepharoseTM 4B. Reverse high pressure liquid chromatography (HPLC), SDS-PAGE and Western blotting were used to analyze the purity and nature of the acquired albumen. Lymphocyte proliferation assay and lymphocytotoxicity assay were used to ditermine the immunological activity of the chaperone-antigen peptide complexes. Results: The chaperone antigen peptide complexes of gastric cancer stem cells were prepared and identified successfully, of which the main components were the antigen peptides of HSP60, HSP70, HSP90 and HSP110. 0.75 µg and 1.00 µg HSP70-antigen peptide and 1.00 µg HSP90-antigen peptide activated lymphocytes significantly. Their A(490) values were 0.26±0.03, 0.45±0.05 and 0.32±0.04, respectively, while the corresponding doses of HSP60-antigen peptide and HSP110-antigen peptide did not activate lymphocytes. The killing rates of 1.00 µg HSP70-antigen peptide and 1.00 µg HSP70 were (45.0±2.0)% and (16.0±2.0)%, respectively, showing a significant difference (P=0.012). Similarly, the killing rates of 1.00 µg HSP90-antigen peptide and 1.00 µg HSP90 were (36.0±5.0)% and (13.0±4.0)%, respectively, also showing a significant difference (P=0.048). Conclusions: The amount of chaperone antigen peptide complexes in gastric cancer cells is extremely low, but it is obviously increased in gastric cancer stem cells. After purification, the chaperone antigen peptide complexes with high purity can be prepared. The extracted chaperone antigen peptide complexes have stronger immunogenicity, and can be used to make tumor vaccine in vitro, which may have a good application value in the targeted therapy of gastric cancer.

Relationship between brain activity and voiding patterns in healthy preterm neonates.

INTRODUCTION: It remains controversial as to whether the brain affects voiding control in preterm newborns. Constant bladder volume has previously been thought to induce bladder voiding in neonates, with no influence from the brain. Lately, there has been distinct evidence for an existing connection between the central nervous system and bladder voiding in preterm infants, as the voiding reflex arouses neonatal children. Video electroencephalography (EEG) is useful for recording bioelectrical activity of the cerebral cortex and exploring its relationship with voiding patterns in preterm neonates. OBJECTIVE: The objective was to investigate the relationship between voiding patterns and brain activity in healthy preterm neonates by using video-EEG. STUDY DESIGN: Forty-seven healthy preterm neonates (16 females) with a mean postconceptional age (PCA) of 34.1 ± 1.8 weeks were divided according to PCA into three groups: Group I (31-33 weeks, n = 13); Group II (33-35 weeks, n = 14); and Group III (35-37 weeks, n = 20). Video-EEG data from eight cortical regions were recorded from 08:00-12:00, along with 4-hour free voiding patterns and status at voiding (awake/sleep). RESULTS: In Group I, the voiding frequency (VF) was significantly higher and the voiding volume (VV) was significantly lower than in the other groups. There were no significant differences in bladder capacity (BC), bladder capacity/birth weight (BC/BW), postvoiding residual/bladder capacity (PVR/BC), or urinary flow rate (UFR) among the three groups. The Fp1-T3 and Fp2-T4 lead amplitudes significantly differed in Group I and Group II at 5 s before (pre-5), during, and after voiding (post-5). The Fp2-C4 total and theta band lead amplitudes significantly differed across all urination states among the groups. There were no significant differences in electroencephalography frequency among the groups in any urination state. DISCUSSION: There were no significant differences in BC, BC/BW, PVR/BC, or UFR among the three groups, indicating slow bladder function development in preterm neonates. In this study, the EEG amplitude changed in certain pairs of electrodes. These changes might indicate the degree of bladder sensor maturation along with an increasing PCA. This study further suggests that the brain changes in preterm neonates during quiet sleep voiding prominently occur in the right prefrontal cortex and central region. CONCLUSIONS: In preterm neonates, bladder voiding during quiet sleep was accompanied by cortical arousal that might have emanated from a lower center.

Reduction of galectin-3 expression reduces pituitary tumor cell progression.

We investigated the role of galectin 3 in the development and progression of pituitary tumors. We used RNA interference to depress Gal-3 gene expression; MTT and flow cytometry were applied to detect changes in cell proliferation and apoptosis levels in pituitary tumor cells. Expression of apoptosis-associated genes, Bcl-2 and Baxk was analyzed by Western blot. Inhibition of Gal-3 gene expression by RNA interference decreased GH3 cell proliferation and increased cell apoptosis; the expression levels of Gal-3 protein significantly decreased, along with those of Bcl-2, although Bax levels did not change. We conclude that Gal-3 has an important role in pituitary tumor cell proliferation and progression; and it may be useful as a target for the treatment of aggressive pituitary tumors.

Dietary inclusion level and time effects of taurine on broiler performance, meat quality, oxidative status and muscle taurine content.

Two experiments were conducted to investigate the effect of taurine on growth performance, meat quality, oxidative status and muscle taurine content in broilers. In Experiment 1, 50 one-day-old male Cobb chicks were given a diet supplemented with 0, 0.125, 0.50, 2.00 or 8.00 g/kg taurine from 1 to 42 d of age. In Experiment 2, 80 22-d-old male Cobb chicks were given a diet supplemented with 4.00 g/kg taurine for 0, 1, 2 or 3 weeks. Taurine contents of thigh and breast muscle increased linearly with increasing dietary taurine. Taurine supplementation for 1, 2 and 3 weeks significantly increased the taurine content of breast muscle. The taurine contents of liver and thigh meat were significantly increased by taurine supplementation for 3 weeks. The taurine contents of thigh and breast meat from broilers given a diet supplemented with 4 g/kg taurine for 3 weeks increased to 1.89 times the concentrations of the control group. There were no detrimental effects on growth performance, breast or thigh muscle yield, pH value or drip-water loss, and taurine supplementation did not affect the serum carbonyl content. Serum malondialdehyde concentration was significantly decreased by taurine supplementation for 1, 2 or 3 weeks.

Exercise-induced changes of the capillaries in the cortex of middle-aged rats.

Previous studies have shown that running exercise could increase regional cerebral blood flow. There have been previous studies investigating the effects of running exercise on capillary density in the brain and showing that running exercise could induce brain angiogenesis. However, there have been no studies investigating the effects of running exercise on the total volume, total length and total surface area of the capillaries in the cortex. Moreover, sex differences in the effects of running exercise on the capillaries of the cortex have not previously been investigated. The current study was designed to investigate the effects of running exercise on the capillaries in the cortex of middle-aged rats using the new unbiased stereological methods. The present study found that the total length and total surface area of the capillaries in the cortex of running middle-aged female rats were significantly increased, compared to control rats. Our results also reveal that there are sex differences in the effects of running exercise on the capillaries in the cortex of middle-aged rats. These results demonstrate that exercise-induced increases of the capillaries in the female rat cortex might be one of the structural bases for the exercise-induced improvement in the spatial learning capacity of middle-aged female rats. These results provide a baseline for further studies that search for strategies to delay the deleterious effects of brain aging.

Effects of an enriched environment on myelin sheaths in the white matter of rats during normal aging: A stereological study.

We found that an enriched environment (EE) could delay the loss of myelinated fibers in the white matter of rats during normal aging. However, the reasons for the protective effects of EE on the myelinated fibers were unclear. In this present study, via the use of stereological methods, we quantitatively investigated the myelin sheaths and the axons of myelinated fibers in the white matter of rats reared in an EE or a standard environment (SE) during the aging process. The results showed that an EE induced significant increases in the lengths of myelinated fibers, the axon volumes and the myelin sheath volumes of aging rats when compared with SE rats and that the enrichment effects, with the exception of the axon volumes, were sex- and age-independent. The mean diameter of the myelinated fibers, the mean perimeter of the myelin sheaths and the mean thicknesses of the myelin sheaths were not significantly changed. The EE-induced increase in myelinated fibers was mostly observed in those of smaller diameter (<1µm) with thinner myelin sheaths (<0.16µm), which had an optimal axon-fiber ratio (g=0.61). Our results suggest that EE-induced an increase in myelinated fibers in the white matter of aging rats primarily due to marked remyelination and some ongoing myelination.

First Report of Root-Knot Nematode Meloidogyne arenaria Infesting Roots of Anubias barteri in Guangdong, China.

Anubias spp. are very popular aquatic plants that are native to Africa. Anubias barteri is a broadleaf Anubias and is a popular choice for aquariums because of its robust size. In China, broadleaf Anubias is usually planted in sand, with sponges around the rhizome, in small plastic baskets in aquatic plant nurseries. In December 2010, a survey of phytoparasitic nematodes was conducted in the nurseries in Guangzhou, Guangdong Province. Many second-stage juveniles of a Meloidogyne sp. were detected from the roots of A. barteri, but no root galls were found. To identify these juveniles, molecular identification was performed with PCR. The DNA sequence between CO II and l-rRNA of the mitochondrial gene of single juveniles was amplified with universal primers of Meloidogyne, #C2F3 (5'-GGTCAATGTTCAGAAATTTGTGG-3') and #1108 (5'-TACCTTTGACCAATCACGCT-3') (3). The amplified fragments were approximately 1.1 kb long and could not be digested with restrictive enzyme HinfI. The specific fragments were then sequenced. The blast search result revealed that the DNA sequence (GenBank Accession No. JQ446377) had 99 to 100% identity with submitted sequences of Meloidogyne arenaria (GenBank Accession Nos. EU364879, GQ266686, and AY635610). The other extracted juveniles were inoculated into sterile, potted, water spinach (Ipomoea aquatica) in the greenhouse to obtain more nematodes. After 40 days, root galls and female egg masses were clearly observed, and biochemical, molecular, and morphological identifications were conducted. Isoenzyme phenotype (esterase and malate dehydrogenase (MDH) patterns) and the perineal pattern of several gravid females were the same as M. arenaria (1,2), and PCR amplification of single juveniles produced identical fragments as previously found. Single egg masses were collected and juveniles were hatched out and inoculated onto 10 nematode-free plants of A. barteri in a greenhouse. After 40 days, roots of A. barteri exhibited inconspicuous small galls, and the same identification procedures were conducted as mentioned previously. Isoenzyme phenotypes, perineal patterns of adult females, and amplified fragments of single juveniles were identical to those of M. arenaria. M. arenaria is one of the most important root-knot nematodes and causes great losses in many crops around the world (2). To our knowledge, this is the first record of M. arenaria parasitizing aquatic plants of broadleaf Anubias in China and elsewhere, and A. barteri is a new host of M. arenaria. The economic importance of this nematode to A. barteri production is currently unknown. However, because A. barteri is a commercial aquatic plant, more attention should be given by producers to prevent this nematode from becoming an important pathogen. In addition, this finding is very helpful for relevant plant nematode quarantine work. References: (1) P. R. Esbenshade and A. C. Triantaphyllou. J. Nematol. 17:1, 1985. (2) R. N. Perry et al. Root-Knot Nematodes. CABI. Wallingford, UK, 2009. (3) T. O. Powers and T. S. Harris. J. Nematol. 25:1, 1993.

Impact of strain engineering on nanoscale strained InGaAs MOSFET devices.

The strain distributions in the In(0.53)Ga(0.47)As channel regions of the In(0.4)Ga(0.6)As source/drain (S/D) with various lengths and widths were studied via 3D process simulations. The resulting mobility improvement was analyzed. The tensile strain along the transport direction was found to dominate the mobility improvement. The strain along the vertical direction perpendicular to the gate oxide was found to affect the mobility the least, while the strain along the width direction was slightly degraded. The impact of the channel width and length on the performance improvement, such as on the mobility gain, was analyzed via TCAD simulations. The novelty of this paper stems from its study of the impact of the channel width and length on the performance of InGaAs NMOSFETs, such as on their mobility gain, and from its exploration of physical insights for scaling the future III-V MOS devices.

Impact of the nanorod structure on the tandem thin-film solar cell.

The novel thin-film solar cell was investigated with a nanorod structure that could solve the conflict between light absorption and carrier transport in the amorphous silicon (a-Si)/amorphous silicon-germanium (a-SiGe) tandem thin-film solar cell. This structure has an n-type a-Si nanorod array on the substrate, and an a-SiOx p-layer and an a-SiGe i-layer are sequentially grown along the surface of each n-type a-Si nanorod, for the bottom cell. After the above bottom-cell process, a similar process is used to fabricate an amorphous Si p-i-n top cell on the bottom cell. Under sunlight illumination, the light is absorbed along the vertical direction of the nanorod, but as the carrier transport is along the horizontal direction, the nanorod may absorb most of the sunlight. In the meantime, the solar cell is still thin enough for the effective transport of photogenerated carriers.

Treatment with spironolactone for 24 weeks decreases the level of matrix metalloproteinases and improves cardiac function in patients with chronic heart failure of ischemic etiology.

BACKGROUND: The myocardial extracellular matrix is believed to be central to the remodelling that takes place following myocardial infarction. The contribution of markers of collagen metabolism to this process remains less well understood. The present study examined the contribution of some of the markers of collagen metabolism in cardiac remodelling, as well as the effect of spironolactone on the remodelling process. OBJECTIVES: To investigate the pathological contribution of markers of collagen metabolism, including matrix metalloproteinases (MMPs), tissue inhibitors of metalloproteinases (TIMPs), type I collagen carboxyterminal telopeptide (ICTP) and procollagen type I carboxyterminal propeptide (PICP), in cardiac remodelling following ischemic cardiomyopathy, and to examine the pharmacoregulatory effects of spironolactone on collagen metabolism. METHOD: Eighty-six consecutive patients (62 men and 24 women) with chronic heart failure of ischemic etiology (patient group) and 25 age-matched controls were enrolled in the study. The subjects in the patient group were randomly assigned into a spironolactone or nonspironolactone group. Plasma levels of MMP-9, TIMP-1, ICTP and PICP were measured using ELISA and radioimmunoassay techniques. Furthermore, left ventricular diastolic diameter and ejection fraction were assessed using two-dimensional and Doppler echocardiography. RESULTS: The plasma concentrations of MMP-9, TIMP-1 and the MMP-9 to TIMP-1 ratio, as well as ICTP, were significantly increased in the patient group. The PICP to ICTP ratio in the patient group was significantly lower than that in the age-matched control subjects. After a follow-up period of 24 weeks, the PICP to ICTP ratio increased, and MMP-9, TIMP-1 and the MMP-9 to TIMP-1 ratio decreased in the spironolactone subgroup. CONCLUSIONS: Biomarkers of collagen degradation were elevated and correlated with depressed heart function; spironolactone may partially reverse the dysregulation in collagen metabolism.

Thyroid hormone predisposes rabbits to atrial arrhythmias by shortening monophasic action period and effective refractory period: results from an in vivo study.

BACKGROUND: Atrial arrhythmias are common complications of hyperthyroidism, but the underlying mechanisms remain to be further clarified. Thus, in this study, we try to investigate the effects of thyroid hormone on atrial electrophysiology by using a hyperthyroidism model in vivo. MATERIALS AND METHODS: Twenty-four New Zealand white rabbits were randomized into Thyroxine group (no.=12) and Control group (no.=12). In Thyroxine group, Levo-thyroxine (L-T(4)) solution (1 mg/kg x d(-1)) was injected daily into the peritoneum for 2 weeks. In Control group, the same amount of saline was injected. On day 15, 8 rabbits in each group were chosen randomly to receive electrophysiological experiment in vivo, in which electrophysiological parameters and atrial arrhythmias induced by electrical stimulation were recorded and serum thyroid hormone levels were examined. The others were killed so as to exam the L-type calcium current of atrium. RESULTS: Atrial monophasic action potential at 90 repolarization (AMAP(90)) and effective refractory period (AERP) were significantly shorter in Thyroxine group than in Control group (AMAP(90): 103.21+/-1.94 vs 122.14+/-6.13, p<0.01; AERP: 82.69+/-0.99 vs 102.46+/-2.32, p<0.01). There are significant differences in the incidence of atrial arrhythmias between the two groups. The mean peak of L-type calcium current (I(Ca,L)) densities (pA/pF) at -10mV was significantly higher in Thyroxine group than in Control group (-8.59+/-0.68 vs -6.54+/-0.49, no.=8, p<0.001). CONCLUSIONS: In our hyperthyroidism model, thyroid hormone predisposed rabbits to atrial arrhythmias by shortening AMAP and AERP, which might be associated with increased I(Ca,L) current densities in atrium.

Natural killer cells suppress full cycle HCV infection of human hepatocytes.

The role of natural killer (NK) cells in controlling hepatitis C virus (HCV) infection and replication has not been fully delineated. We examined NK cell-mediated noncytolytic effect on full cycle HCV infection of human hepatocytes. Human hepatocytes (Huh7.5.1 cells) co-cultured with NK cells or treated with supernatants (SN) from NK cells cultures had significantly lower levels of HCV RNA and protein than control cells. This NK cell-mediated anti-HCV activity could be largely abolished by antibody to interferon-gamma (IFN-gamma). The investigation of the mechanisms for NK cell-mediated anti-HCV activity showed that NK SN-treated hepatocytes expressed higher levels of IFN-alpha/beta than the control cells. NK SN also enhanced IFN regulatory factor-3 and 7 expression in the hepatocytes. In addition, NK SN enhanced the expression of signal transducer and activator of transcription 1 and 2, the nuclear factors that are essential for the activation of IFN-mediated antiviral pathways. These data provide direct evidence at cellular and molecular levels that NK cells have a key role in suppressing HCV infection of and replication in human hepatocytes.

Troponin T measurement can predict persistent left ventricular dysfunction in peripartum cardiomyopathy.

OBJECTIVE: To determine whether measurement of cardiac troponin T (cTnT) concentration in newly diagnosed peripartum cardiomyopathy (PPCM) can be used to predict persistent left ventricular dysfunction after a 6-month follow-up. PATIENTS AND METHODS: This was a prospective, multiple-centre clinical trial that studied 106 patients with newly diagnosed PPCM surviving over 6 months. cTnT concentration was measured within 2 weeks of the onset of PPCM. RESULTS: Serum cTnT concentration was negatively correlated with left ventricular ejection fraction (LVEF) at follow-up (LVEF, r = -0.518, p = 0.0001). Analysis by receiver operator characteristic curve yielded an area under the curve of 0.764 (95% CI 0.669 to 0.860, p = 0.0001, vs null hypothesis value 0.5) for cTnT, and a cTnT concentration cut off of >0.04 ng/ml, predicting persistent left ventricular dysfunction with a sensitivity of 54.9% and a specificity of 90.9%. Among 106 recruited patients, there were 33 patients with cTnT concentrations >0.04 ng/ml and 73 patients with cTnT concentrations < or =0.04 ng/ml. After a 6-month follow-up, there was significantly smaller LVEF (35.42% (13.04% vs 50.16% (10.48%, p = 0.0001) and more persistent left ventricular dysfunction (84.8% vs 31.5%, OR = 12.17 (95% CI 4.17 to 35.57), p = 0.001) in patients with cTnT >0.04 ng/ml than in patients with cTnT < or =0.04 ng/ml. CONCLUSION: Serum cTnT concentration measured within 2 weeks of the onset of PPCM was correlated negatively with LVEF at follow-up. This marker offers a simple, quick, inexpensive, non-invasive method for predicting a persistent LVEF of < or =50%. A cTnT concentration of >0.04 ng/ml predicted persistent left ventricular dysfunction with a sensitivity of 54.9% and a specificity of 90.9%.

Freeze/thaw-induced embolism depends on nadir temperature: the heterogeneous hydration hypothesis.

Freeze/thaw-induced embolism was studied in leaves of field-grown snow gum (Eucalyptus pauciflora) subject to frequent morning frosts. Juvenile trees were grown in buried pots, brought to the laboratory at different stages of acclimation and subjected to simulated frost-freezes (at 2 degrees C h(-1)) to nadir temperatures of -3 or -6 degrees C, which snow gums commonly experience. Frost-frozen and subsequently thawed leaves were cryo-fixed to preserve the distribution of water and were then examined by cryo-scanning electron microscopy. No embolisms were found in leaves frozen to -3 degrees C and thawed. In contrast, 34% of vessels were embolized in thawed leaves that had been frozen to -6 degrees C. This difference was seen also in the extent of extracellular ice blocks in the mid-vein expansion zones in leaves frozen to -3 and -6 degrees C, which occupied 3 and 14% of the mid-vein area, respectively. While the proportion of embolism depended on nadir temperature, it was independent of season (and hence of acclimation state). From the observation that increased embolism at lower nadir temperature was related to the freeze-induced redistribution of water, we hypothesize that the dehydration of cell walls and cells caused by the redistribution exerts sufficient tension on xylem water to induce cavitation on thawing.