Boundary migration in a 3D deformed microstructure inside an opaque sample

How boundaries surrounding recrystallization grains migrate through the 3D network of dislocation boundaries in deformed crystalline materials is unknown and critical for the resulting recrystallized crystalline materials. Using X-ray Laue diffraction microscopy, we show for the first time the migration pattern of a typical recrystallization boundary through a well-characterized deformation matrix. The data provide a unique possibility to investigate effects of both boundary misorientation and plane normal on the migration, information which cannot be accessed with any other techniques. The results show that neither of these two parameters can explain the observed migration behavior. Instead we suggest that the subdivision of the deformed microstructure ahead of the boundary plays the dominant role. The present experimental observations challenge the assumptions of existing recrystallization theories, and set the stage for determination of mobilities of recrystallization boundaries.

[Clinical features of postoperative cervical lymph nodes recurrence in papillary thyroid carcinoma]

Objective: To analyse the postoperative metastasis or recurrence of cervical lymph nodes in individual neck levels for papillary thyroid carcinoma and to evaluate the outcomes and complications of re-surgery. Methods: A retrospective cohort study of 259 patients who underwent lymph node dissection for PTC relapse from January 2010 to June 2011. Lymph node metastases in each of neck levels were detected, postoperative complications were evaluated, and the patients were followed up with examining thyroglobulin levels to assess the therapeutic effect.Continuous variables were compared with t test.Categorical variables were compared with Fisher's exact test. Results: Lymph node metastasis was found in 259 cases and lymph node metastasis rates in levels Ⅱ, Ⅲ, Ⅳ, Ⅴ and Ⅵ were 43.2%, 50.2%, 45.6%, 8.1% and 59.1% respectively. In 44 cases received the neck dissection of level Ⅱ, the metastasis rates in the levels Ⅱa and Ⅱb were respectively (52.3% vs 18.2%, P=0.887). Recurrence in unilateral lateral neck was more common than that in bilateral lateral neck (73.1% vs 20.6%, P<0.001). The lymph nodes in lateral neck were more likely to metastasize than those in central region (80.7% vs 59.1%, P<0.001). There were 47 cases (18.1%) had postoperative complications, including 10 cases with permanent hypocalcemia. Conclusions: The scope of re-operation for neck metastasis or recurrence in papillary thyroid carcinoma should include the dissection of levels Ⅱ-Ⅳ and Ⅵ. The incidence of postoperative complications for re-surgery is high, and re-surgery should be performed by experienced surgeon.

mRNA and protein expression levels of four candidate genes for ear size in Erhualian and Large White pigs

Porcine ear size is an important characteristic for distinguishing among pig breeds. In a previous genome-wide association study of porcine ear size, LEM domain-containing 3 (LEMD3), methionine sulfoxide reductase B3 (MSRB3), high mobility group AT-hook 2 (HMGA2), and Wnt inhibitory factor 1 (WIF1) were implicated as important candidate genes for ear size. This study investigated the expression levels of four candidate genes for ear size in Erhualian and Large White pigs. Ten Erhualian pigs with large ears and eight Large White pigs with small ears at 60 days of age were examined. The mRNA expression levels of the four candidate genes were quantified by real-time polymerase chain reaction. WIF1 mRNA expression was significantly higher in Large White than in Erhualian pigs (P < 0.05), whereas the expression levels of the other three genes were not significantly different between the two breeds. The protein expression levels of the four genes were analyzed using western blot. WIF1 protein expression was significantly higher in Large White than in Erhualian pigs (P < 0.01), whereas MSRB3 protein expression was significantly higher in Erhualian than in Large White pigs (P < 0.05). There were no significant differences between the two breeds in residual protein expression. These results suggest that WIF1 is the main causal gene for ear size in pigs.

[Central compartment reoperation for recurrent/persistent differentiated thyroid cancer]

Objective: To analyze the incidences of complications after central compartment reoperation for recurrent/persistent differentiated thyroid cancer, and to investigate the safety and feasiblity of central compartment reoperation. Methord: A total of 109 patients who underwent central compartment reoperation for recurrent/persistent differentiated thyroid cancer from January 1, 2011 to March 31, 2016 in Cancer Hospital, Chinese Academy of Medical Sciences was analysed retrospectively, and the incidences of reoperation-related complications were evaluated. Results: Among 109 patients, only 10 (9.2%) patients were treated initially in our hospital and remaining patients (90.8%) treated initially in the other hospitals. Surgical approaches for thyroid beds: 61 patients (56.0%) underwent supplemented total thyroidectomy, 3 patients (2.8%) for removal of recurrent thyroid cancer, 2 patients (1.8%) with supplemented total thyroidectomy and removal of recurrent thyroid cancer, and 12 cases (11.0%) had bilateral thyroid lobectomy. Central compartment lymph node dissection: 66 patients (60.6%) underwent bilateral central neck dissection, 40 patients (36.7%) with unilateral central neck dissection. A total of 16 patients (14.7%) had complications. Transient and permanent vocal fold paralysis developed in 9(8.3%) and 2(1.8 %) patients, respectively. Transient and permanent hypoparathyroidism occurred in 2(1.8%) patients and 11 patients (10.1%), respectively. Postoperative bleeding happened in 1 patient (0.9%). with follow-up from 7 to 61 month, median follow-up was 17.2 months. All patients survived, with recurrence in 3 (2.8%) patients. Conclusions: It seems the incidences of complications for thyroid carcinoma reoperation in central compartment is low for the experienced surgeon. The reoperation was safe and feasible.

Comparison of chemical profiles and effectiveness between Erxian decoction and mixtures of decoctions of its individual herbs: a novel approach for identification of the standard chemicals

Background

Identification of bioactive standard chemicals is a major challenge in the study of the Chinese medicinal formula. In particular, the chemical components may interact differently depending on the preparative methods, therefore affecting the amounts of bioactive components and their pharmacological properties in the medicinal formula. With the use of Erxian decoction (EXD) as a study model—a  well-known Chinese medicinal formula for treating menopausal symptoms, a novel and rapid approach in seeking standard chemicals has been established by differentially comparing the HPLC profiles and the menopause-related biochemical parameters of combined decoction of EXD (EXD-C) and mixtures of the decoctions of its individual herbs (EXD-S).

Methods

The levels of six chemicals, which exerted actions on the HPO axis, have been measured in EXD-C and EXD-S by HPLC. Twelve-month-old female Sprague-Dawley rats were employed and treated with EXD-C and EXD-S. Their endocrine functions after treatment were evaluated by determining the ovarian mRNA levels of aromatase, a key enzyme for estradiol biosynthesis. The effect of the antioxidant regimen was determined by the hepatic superoxide dismutase-1 (SOD), catalase (CAT) and glutathione peroxidase (GPx-1) mRNA levels.

Results

The amounts of mangiferine, ferulic acid, jatrorrhizine and palmatine in EXD-S were twofold higher than those in EXD-C. EXD-S was more effective in stimulating ovarian aromatase and the expression of the antioxidant enzymes compared with EXD-C.

Conclusion

Mangiferine, ferulic acid, jatrorrhizine and palmatine are suitable for use as standard chemicals for quality evaluation of EXD according to our approach. EXD-S could be more effective than EXD-C.

A method to characterize the roughness of 2-D line features: recrystallization boundaries

A method is presented, which allows quantification of the roughness of nonplanar boundaries of objects for which the neutral plane is not known. The method provides quantitative descriptions of both the local and global characteristics. How the method can be used to estimate the sizes of rough features and local curvatures is also presented. The potential of the method is illustrated by quantification of the roughness of two recrystallization boundaries in a pure Al specimen characterized by scanning electron microscopy.

Porcine MAP3K5 analysis: molecular cloning, characterization, tissue expression pattern, and copy number variations associated with residual feed intake

Mitogen-activated protein kinase kinase kinase 5 (MAP3K5) is essential for apoptosis, proliferation, differentiation, and immune responses, and is a candidate marker for residual feed intake (RFI) in pig. We cloned the full-length cDNA sequence of porcine MAP3K5 by rapid-amplification of cDNA ends. The 5451-bp gene contains a 5'-untranslated region (UTR) (718 bp), a coding region (3738 bp), and a 3'-UTR (995 bp), and encodes a peptide of 1245 amino acids, which shares 97, 99, 97, 93, 91, and 84% sequence identity with cattle, sheep, human, mouse, chicken, and zebrafish MAP3K5, respectively. The deduced MAP3K5 protein sequence contains two conserved domains: a DUF4071 domain and a protein kinase domain. Phylogenetic analysis showed that porcine MAP3K5 forms a separate branch to vicugna and camel MAP3K5. Tissue expression analysis using real-time quantitative polymerase chain reaction (qRT-PCR) revealed that MAP3K5 was expressed in the heart, liver, spleen, lung, kidney, muscle, fat, pancrea, ileum, and stomach tissues. Copy number variation was detected for porcine MAP3K5 and validated by qRT-PCR. Furthermore, a significant increase in average copy number was detected in the low RFI group when compared to the high RFI group in a Duroc pig population. These results provide useful information regarding the influence of MAP3K5 on RFI in pigs.

Influence of spatial incident angles on polarizer with a slit in grooved metal slabs for terahertz communication

We report the influence of two spatial incident angles on a terahertz polarizer, which is based on an aluminum slab with a center slit flanked by symmetrically distributed parallel grooves on both sides. Experimental results show that the polarizer shows narrow bandpass filtering effect with a very small divergence angle at normal incidence, which is very suitable for terahertz communication, and the extinction ratio (ER) can be achieved above 20 dB in the frequency band between 0.3 and 0.36 THz due to the excitation of spoof surface plasmon. As the structure rotates around the slit direction (β), the transmission peak will split into two and degrade quickly and the ER decreased down to 20 dB for β=10° at peak position. Rotating along grating period direction (γ) shows better tuning performance. The tuning frequency window can reach from 0.3 to 0.36 THz to promise an ER above 20 dB as γ is smaller than 25°.

Cloning and sequence analysis of the Blumea balsamifera DC farnesyl diphosphate synthase gene

Blumea balsamifera DC is a member of the Compositae family and is frequently used as traditional Chinese medicine. Blumea balsamifera is rich in monoterpenes, which possess a variety of pharmacological activities, such as antioxidant, anti-bacteria, and anti-viral activities. Farnesyl diphosphate synthase (FPS) is a key enzyme in the biosynthetic pathway of terpenes, playing an important regulatory role in plant growth, such as resistance and secondary metabolism. Based on the conserved oligo amino acid residues of published FPS genes from other higher plant species, a cDNA sequence, designated BbFPS, was isolated from B. balsamifera DC using polymerase chain reaction. The clones were an average of 1.6 kb and contained an open reading frame that predicted a polypeptide of 342 amino acids with 89.07% identity to FPS from other plants. The deduced amino acid sequence was dominated by hydrophobic regions and contained 2 highly conserved DDxxD motifs that are essential for proper functioning of FPS. Phylogenetic analysis indicated that FPS grouped with other composite families. Prediction of secondary structure and subcellular localization suggested that alpha helices made up 70% of the amino acids of the sequence.

DNA methylation regulates expression of VEGF-C, and S-adenosylmethionine is effective for VEGF-C methylation and for inhibiting cancer growth

DNA hypomethylation may activate oncogene transcription, thus promoting carcinogenesis and tumor development. S-adenosylmethionine (SAM) is a methyl donor in numerous methylation reactions and acts as an inhibitor of intracellular demethylase activity, which results in hypermethylation of DNA. The main objectives of this study were to determine whether DNA hypomethylation correlated with vascular endothelial growth factor-C (VEGF-C) expression, and the effect of SAM on VEGF-C methylation and gastric cancer growth inhibition. VEGF-C expression was assayed by Western blotting and RT-qPCR in gastric cancer cells, and by immunohistochemistry in tumor xenografts. VEGF-C methylation was assayed by bisulfite DNA sequencing. The effect of SAM on cell apoptosis was assayed by flow cytometry analyses and its effect on cancer growth was assessed in nude mice. The VEGF-C promoters of MGC-803, BGC-823, and SGC-7901 gastric cancer cells, which normally express VEGF-C, were nearly unmethylated. After SAM treatment, the VEGF-C promoters in these cells were highly methylated and VEGF-C expression was downregulated. SAM also significantly inhibited tumor growth in vitro and in vivo. DNA methylation regulates expression of VEGF-C. SAM can effectively induce VEGF-C methylation, reduce the expression of VEGF-C, and inhibit tumor growth. SAM has potential as a drug therapy to silence oncogenes and block the progression of gastric cancer.

Genetic diversity of the Chinese traditional herb Blumea balsamifera (Asteraceae) based on AFLP markers

Blumea balsamifera is a commercially important medicinal herb in China and other parts of Asia. It is used to produce borneol. This plant grows in the wild, but resources have diminished greatly in recent years. We examined the genetic diversity of this species to help develop conservation strategies; 35 plants from five provinces were analyzed using AFLPs. Eight AFLP primer combinations generated 1367 fragments, giving a mean of 172 fragments per primer combination. Polymorphism in the germplasm analysis was found for 1360 (99.48%) of the fragments, of which 264 (19.27%) fragments were unique (accession specific) and 423 (25.33%) of the fragments were rare (present in less than 10% of the accessions). The polymorphic fragments were used to group the accessions in a UPGMA phenogram. Most grouping was geographical. In general, accessions coming from Guizhou and Guangxi showed higher diversities as these accessions were scattered in different groups. The genetic distance estimated by Jaccard similarity coefficient index showed low variability among genotypes (coefficient value ranged from 0.60 to 0.95). More attention should be given to the study and conservation of the biodiversity of this economically important genus.

Ultrasound-assisted extraction and purification of schisandrin B from Schisandra chinensis (Turcz.) Baill seeds: optimization by response surface methodology

The objective of this study is to develop a process consisting of ultrasonic-assisted extraction, silica-gel column chromatography and crystallization to optimize pilot scale recovery of schisandrin B (SAB) from Schisandra chinensis seeds. The effects of five independent variables including liquid-solid ratio, ethanol concentration, ultrasonic power, extraction time, and temperature on the SAB yield were evaluated with fractional factorial design (FFD). The FFD results showed that the ethanol concentration was the only significant factor for the yield of SAB. Then, with the liquid-solid ratio 5 (mL/g) and ultrasonic power 600 W, the other three parameters were further optimized by means of response surface methodology (RSM). The RSM results revealed that the optimal conditions consisted of 95% ethanol, 60 °C and 70 min. The average experimental SAB yield under the optimum conditions was found to be 5.80 mg/g, which was consistent with the predicted value of 5.83 mg/g. Subsequently, a silica gel chromatographic process was used to prepare the SAB-enriched extract with petroleum ether/acetone (95:5, v/v) as eluents. After final crystallization, 1.46 g of SAB with the purity of 99.4% and the overall recovery of 57.1% was obtained from 400 g seeds powder. This method provides an efficient and low-cost way for SAB purification for pharmaceutical industrial applications.

Ferromagnetism in ZnO:Co originating from a hydrogenated Co-O-Co complex

The effects of hydrogen interstitials and oxygen vacancies on the overall ferromagnetic behaviour of Co doped ZnO (ZnO:Co) have been closely examined using different density functional calculations. The results demonstrate the importance of correcting the bandgap problem of the ZnO host as well as the lack of correlation in Co's 3d states which can severely affect the coupling of H and Co's impurity bands. Our results show that in hydrogenated ZnO:Co, hydrogen interstitial can also stabilize the ferromagnetic interaction at low Co concentrations, but this requires the formation of the in-plane O-H-Co-O-Co complex. In this structure, the hydrogen interstitial forms an anionic complex with the neighbouring oxygen, which polarizes the surrounding oxygen to mediate the ferromagnetism through the superexchange mechanism. An oxygen vacancy by itself would not cause ferromagnetism in ZnO:Co. On the other hand, in the presence of hydrogen interstitials, oxygen vacancies can significantly enhance the magnetic coupling between H and Co-O-Co as a shallow donor if it is far away from the in-plane O-H-Co-O-Co complex. However, the total energy results show that this is much more favoured when the oxygen vacancy is near the in-plane O-H-Co-O-Co complex, which can inhibit the ferromagnetic interaction between Co ions.

In silico study of Aquaporin V: Effects and affinity of the central pore-occluding lipid

Because of its roles in human physiology, Aquaporin V (AQP5), a major intrinsic protein, has been a subject of many in vitro studies. In particular, a 2008 experiment produced its crystal structure at 2.0Å resolution, which is in a tetrameric conformation consisting of four protomers. Each protomer forms an amphipathic pore that is fit for water permeation. The tetramer has a pore along its quasi-symmetry axis formed by quadruplets of hydrophobic residues (every protomer contributes equally to the quadruplets). A lipid, phosphatidylserine (PS6), is bound to AQP5 in the central pore, totally occluding it. A 2009 experiment showed that AQP5 facilitates not only permeation of water but also permeation of hydrophobic gas molecules across the cell membrane. In this article, we present an in silico study of AQP5 to elucidate the effects of PS6's binding to and dissociating from AQP5's central pore. Computing the lipid's chemical-potential along its dissociation path, we find that PS6 inhibits the function of the central pore with an IC(50) in the micromolar range. Examining the central pore and the interstices between two adjacent protomers, we propose that nonpolar gas molecules (O(2)) permeate through AQP5's hydrophobic central pore when un-occluded.

Solvothermal route to S-deficient CoS nanoplates and their cathodoluminescence and magnetic properties

A facile solvothermal method was developed to fabricate CoS nanoplates using ethylenediamine as solvent. The microstructure characterizations indicate that the CoS nanoplates have well-crystalline hexagonal phase and regular hexagonal or pentagonal shape. The XPS and ICP-AES measurements confirm the chemical composition of nanoplates is S-deficient CoS0.921. Cathodoluminescence spectra of both a large area of the nanoplates and individual nanoplate show broad emission bands centered at 615 nm. Magnetic measurements including magnetization dependence of temperature and magnetic hysteresis loops reveals that the CoS nanoplates exhibit room-temperature ferromagnetic behavior. It is found that intrinsic point defects mainly as V(s), Co(i) and/or the complex defects of V(s) and Co(i) should be responsible for both the broad emission band and the unique ferromagnetism.

Reliability of the Fukuda stepping test to determine the side of vestibular dysfunction

The Fukuda stepping test (FST) is widely used in neurology and for the diagnosis of vertigo-associated disease, but its reliability is disputed. This study assessed the accuracy of the FST in determining the side of vestibular dysfunction in 126 patients with unilateral vestibular lesion. Abnormal deviation towards the side of the lesion occurred in 50.0% of cases and towards the intact side in 24.6% of cases, with 25.4% of patients within the normal range (< 45° deviation). An equal percentage of patients with acute stage vertigo (0-3 days after onset) deviated towards the intact and lesion sides, however the percentage of patients deviating to the intact side decreased over time. A subset of patients who originally deviated towards the intact side gradually began to deviate towards the lesion side. Care should be taken when using the FST to determine the side of the lesion, particularly in acute stage vertigo.

EZH2 silencing by RNA interference inhibits proliferation in bladder cancer cell lines

The Enhancer of Zeste homologue2 gene (EZH2) is frequently expressed at high levels in malignant tumours, including bladder cancer. It functions as a transcriptional regulator to the maintenance of cell identity, cell cycle regulation and oncogenesis. In the study, we detected EZH2 expression in bladder cancer tissues. These results showed EZH2 high expression in bladder cancer tissue at level of transcript and protein compared with normal bladder tissue and EZH2 expression correlated positively with tumour stage and grade. Then, we used RNA interference to inhibit EZH2 expression in bladder cancer EJ cell line. Efficient downregulation of EZH2 resulted in significantly decreased cell proliferation in EJ cells and retarded transition of G(1) phase to S phase. Our data suggest that EZH2 is involved in the tumourigenesis of bladder cancer and EZH2 downregulation contributes to inhibiting malignant growth by retarding cell entrance to S phase.

Partial response of hepatocellular carcinoma to percutaneous microwave ablation: risk factors and preventive measures

AIM: To investigate the risk factors and preventive measures for partial response of hepatocellular carcinoma to percutaneous microwave ablation.

METHODS: The clinical data for 465 patients with hepatocellular carcinoma (796 tumor nodules) who underwent percutaneous microwave ablation from October 2004 to June 2010 were retrospectively analyzed. The risk factors and preventive measures for partial response to percutaneous microwave ablation were summarized.

RESULTS: Partial response occurred in 48 patients (69 tumor nodules), and the overall partial response rate was 9.15% (69/754). Of these 48 patients, 45 (64 tumor nodules) underwent percutaneous microwave ablation again and achieved complete ablation in 93.94% (62/64) of tumor nodules; 1 (2 tumor nodules) received percutaneous ethanol injection and achieved successful ablation; and 2 received palliative surgery. The incidence of partial response was positively correlated with large tumor diameter, tumor location (at the hepatic hilum or near the diaphragm or hepatic capsule), multiple tumors, and ill-defined margins on ultrasound(all P < 0.01), and complete ablation was negatively correlated with previous treatment by TACE (3.60% vs 12.39%, P < 0.01). Multivariate analysis showed that tumor size, number of nodules, tumor location, and previous treatment by TACE were independent risk factors for partial response of hepatocellular carcinoma to percutaneous microwave ablation.

CONCLUSION: Large tumor size, multiple tumors, subcapsular lesion, and previous treatment by TACE are often associated with partial response of hepatocellular carcinoma to percutaneous microwave ablation. Percutaneous microwave ablation is an effective and safe method for treatment of partial response of hepatocellular carcinoma.

Structure, stability and magnetism of cobalt doped (ZnO)n clusters

Clusters of magnetic impurities are believed to play an important role in retaining ferromagnetism in diluted magnetic semiconductors (DMS), the origin of which has been a long debated issue. Controlling the dopant homogeneity in magnetic semiconductors is therefore a critical issue for the fabrication of high performance DMS. The current paper presents a first principle study on the stability and magnetic properties of Co doped (ZnO)n (n = 12 and 15) clusters using density functional theory. The results show that cobalt ions in these clusters tend to increase their stabilities by maximizing their co-ordination numbers to oxygen. This will likely to be the case for (ZnO)n clusters with n other than 12 and 15 in order for Co to reside in a stable local crystal field. Expansive (shrinkage) stress is introduced when cobalt resides in exohedral substitutional (endohedral interstitial) sites; such strain can be offset by the cluster deformation. Bidoped cluster is found to be unstable due to the increase of system strain energy. All the doped clusters were found to preserve 3 microg of magnetic moments from Co in the overall clusters, but with part of the local moments on cobalt re-distributed onto neighboring oxygen atoms. Current findings may provide a better understanding on the structural chemistry of magnetic dopants in nanocrystallined DMS materials.

Structural and magnetic stability of dopants in ZnO-based dilute magnetic semiconductors

Structural and magnetic configurations of Co/Mn ions, the most widely studied transition metal dopants in ZnO-based dilute magnetic semiconductors, have been investigated using first-principles density functional calculations. The study provides a fundamental theoretical understanding on the distribution of the magnetic ions in the ZnO host and its corresponding magnetism. Results show that the substituent magnetic ions at the Zn site strongly tend to aggregate chain-like via oxygen on the ab plane with an antiferromagnetic coupling in contrast to paramagnetic isolated free Co/Mn. Substitutional Cu codoping is found theoretically to reduce the magnetic dopant's tendency towards chain-like aggregation, in good agreement with recent experimental observations.

The feeble role of oxygen vacancies in magnetic coupling in ZnO based dilute magnetic semiconductors

The role of the oxygen vacancy (V(O)) as the dominant defect in ZnO in magnetic interactions of ZnO based dilute magnetic semiconductors (DMSs) was examined in detail using density functional theory. It was found that V(O) does not lead to a thermally activated carrier mediated magnetism or form magnetic centers in the ZnO lattice. However, neutral V(O) may facilitate the ferromagnetism, but has a limited influence on the original antiferromagnetic coupling of the magnetic ions in oxygen stoichiometric ZnO DMSs. As a result, the ferromagnetism observed in previous experiments should be attributed to other defects such as hydrogen contamination or zinc interstitials.

Predominant role of defects in magnetic interactions in codoped ZnO:Co

The roles of codoping ions (Li, Ga and Cu) and defects (oxygen vacancy and hydrogen impurity) in magnetic interactions in ZnO:Co systems have been studied systematically using an ab initio method with density functional theory and the standard molecular field model. The results show that where defects are not included in ZnO's lattice carrier mediated magnetism is only achievable in shallow p-type codoping, such as ZnO:Co + Cu. However, in deep p-type codoping (ZnO:Co + Li) and deep n-type codoping (ZnO:Co + Ga), the carriers generally do not induce spontaneous magnetism. It was also found that the oxygen vacancy, due to its deep donor nature, has a minor favoring effect on ferromagnetic ordering among Co ions. The observed ferromagnetism in such systems can be attributed to the interaction of Co ions with unintentional hydrogen contamination rather than codopants or oxygen vacancies.

Hydrogen multicenter bond mediated magnetism in Co doped ZnO

Magnetism in Co doped ZnO (ZnO:Co) is strongly affected by the presence of the ZnO's extrinsic impurities, such as unintentional hydrogen dopants. Our ab initio investigation reveals that in ZnO:Co the formation of substitutional H (H(O)) with four-fold hydrogenic bonds is favored over interstitial hydrogen (H(I)) by 0.4 eV. It is found that H(O) is trapped by Co ions to form highly stable Co-H(O)-Co complexes. H(O) also mediates a strong short-ranged ferromagnetic interaction between Co dopants via short-range exchange interaction which induces room temperature ferromagnetism.

Substantial stabilization of ferromagnetism in ZnO:Mn induced by N codoping

Electronic structures and magnetic properties of ZnO:Mn and ZnO:Mn+N systems are investigated using first-principles density functional calculations with generalized gradient approximation. The results provide a fundamental theoretical understanding in the substantial ferromagnetic stability induced by N codoping in the ZnO:Mn system observed experimentally. They demonstrate that the ferromagnetic interaction is due to the hybridization between N 2p and Mn 3d states and is very sensitive to the geometrical configurations of dopants in the ZnO host lattice. The most stable ferromagnetic configuration corresponds to the Mn-N-Mn cluster, energetically strong enough to lead to hole-mediated ferromagnetism at room temperature.

A novel mechanism: Erxian Decoction, a Chinese medicine formula, for relieving menopausal syndrome

ETHNOPHARMACOLOGICAL RELEVANCE

Many clinical and experimental reports demonstrated that Erxian Decoction (EXD) was effective in relieving menopausal syndrome.

AIM OF THE STUDY

The mechanisms of action of EXD were explored on the endocrine and antioxidant regimen.

MATERIALS AND METHODS

Menopause causes a decline in both endocrine function and activities of antioxidant enzymes. In this study, 12-month-old female Sprague-Dawley-rats (SD-rats) with a low serum estradiol level were employed. Their endocrine functions after treatment with EXD were assessed by the determination of their serum estradiol level and ovarian mRNA levels of aromatase, which is a key enzyme for biosynthesis of estradiol. Meanwhile, superoxide dismutase-1 (SOD), catalase (CAT) and glutathione peroxidase (GPx-1) in the liver were also determined to assess the effect of EXD on the antioxidant regimen.

RESULTS

Results revealed a significant elevation in serum estradiol level and the mRNA level of ovarian aromatase and liver CAT in the EXD-treated menopausal rat model.

CONCLUSIONS

The results obtained from mRNA and estradiol level of the present investigation revealed that the EXD relieves the menopausal syndrome involved an increase of endocrine and antioxidant function through, at least, the activation of aromatase and CAT detoxifying pathways.

Isolation and aggregation of substituent Co in ZnO:Co diluted magnetic semiconductors

Distribution of magnetic ions in a semiconducting host is critical for the functionality of diluted magnetic semiconductors. By investigating the temperature- and field-dependent magnetization of single-phase polycrystalline ZnO:Co oxides, the substitution of Co at the Zn site is found not to occur randomly but Co ions appear to have a tendency for aggregation via oxygen with an antiferromagnetic coupling, in contrast to paramagnetic isolated free Co. The experimental findings are justified through first-principles density functional calculations based on the generalized gradient approximation. It suggests that Co dopants in ZnO:Co have a tendency towards staying close to each other along the ab plane.

Antimicrobial activity-specific to Gram-negative bacteria and immune modulation-mediated NF-kappaB and Sp1 of a medaka beta-defensin

Defensins are a group of cationic antimicrobial peptides which play an important role in the innate immune system by exerting their antimicrobial activity against pathogens. In this study, we cloned a novel beta-defensin cDNA from medaka (Oryzias latipes) by rapid amplification of cDNA ends (RACE) technique. The full-length cDNA consists of 480 bp, and the open reading frame (ORF) of 189 bp encodes a polypeptide of 63 amino acids (aa) with a predicted molecular weight of 7.44 kDa. Its genomic organization was analyzed, and Southern blot detection confirmed that only one copy of beta-defensin exists in the medaka HNI strain. RT-PCR, Western blot and immunohistochemistry detections showed that the beta-defensin transcript and protein could be detected in eyes, liver, kidney, blood, spleen and gill, and obviously prevalent expression was found in eyes. Antimicrobial activity of the medaka beta-defensin was evaluated, and the antibacterial activity-specific to Gram-negative bacteria was revealed. Furthermore, the lipopolysaccharide (LPS), a major component of the outer membrane of Gram-negative bacteria, was demonstrated to be able to induce about 13-fold up-regulation of the beta-defensin within first 12h. In addition, promoter and promoter mutagenesis analysis were performed in the medaka beta-defensin. A proximal 100 base pair (bp) sequence (+26 to -73) and the next 1700 bp sequence (-73 to -1755) were demonstrated to be responsible for the basal promoter activity and for the transcription regulation. Three nuclear factor kappa B (NF-kappaB) cis-elements and a Sp1 cis-element were revealed by mutagenesis analysis to exist in the 5' flanking sequence, and they were confirmed to be responsible for the up-regulation of medaka beta-defensin stimulated by LPS. And, the Sp1 cis-element was further revealed to be related to the basal promoter activity, and transcriptional factor II D (TFIID) was found to be in charge of the gene transcription initiation. All the obtained data suggested that the novel medaka beta-defensin should have antimicrobial activity-specific to Gram-negative bacteria, and the antibacterial immune function should be modulated by NF-kappaB and Sp1.

A PstI polymorphism at 3'UTR of goat POU1F1 gene and its effect on cashmere production

POU1F1 is a positive regulator for prolactin (PRL) whose metabolites may directly or indirectly affect some aspects of the hair growth cycle, therefore, POU1F1 gene is an important candidate gene for cashmere traits selection through marker-assisted selection (MAS). Hence, in this study, the PCR-RFLP method was applied to detect a T>C transition determining a PstI polymorphism at the 3'UTR of POU1F1 locus and evaluate its associations with cashmere traits in 847 Inner Mongolia White Cashmere goats. In the analyzed population, the allelic frequencies for the T and C alleles are 0.959 and 0.041, respectively and the genotypic frequencies are in Hardy-Weinberg equilibrium (P > 0.05). Moreover, significant statistical relationships between the PstI polymorphism of POU1F1 gene and goat cashmere yields were found (*P < 0.05). When compared with TC genotype, TT genotype was associated with superior cashmere yields in 2, 4, and 5 years old individuals, as well as with average cashmere yield. Hence, TT genotype is suggested to be a molecular marker for senior cashmere yield.

Microwave assisted catalytic oxidation of p-nitrophenol in aqueous solution using carbon-supported copper catalyst

Carbon-supported copper (Cu/GAC) catalyst was prepared by conventional impregnation method and characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD). The sizes of Cu particles dispersing on the surface of GAC were 0.3-1.5 microm, which could be penetrated by microwave so that Cu/GAC catalyst could absorb microwave energy effectively. The catalysis of Cu/GAC in microwave assisted catalytic oxidation of p-nitrophenol (PNP) in aqueous solution was investigated through a fixed bed reactor under ambient pressure and continuous flow mode. PNP removal reached 91.8% under optimized conditions, corresponding to 88% of TOC removal. It showed a higher PNP degradation and total organic carbon (TOC) removal for Cu/GAC catalyst than GAC alone, and Cu/GAC catalyst kept on a high catalysis and a good stability for a long time run, which indicated that GAC structure and catalytic capacity were improved by the load of Cu.

Immunosuppressive Activity of Semen Persicae Ethanol Extract on Specific Antibody and Cellular Response to Ovalbumin in Mice

The immunosuppressive activity of the ethanol extract of Semen Persicae (EESP) was studied with respect to specific antibody and cellular response to ovalbumin (OVA) in mice. The effects of EESP on mice splenocyte proliferation in vitro were measured. EESP significantly suppressed concanavalin A (ConA)- and lipopolysaccharide (LPS)-stimulated splenocyte proliferation in vitro in a concentration-dependent manner. Furthermore, the effects of EESP at three dose levels on the humoral and cellular immune responses in the OVA-immunized mice were examined. ICR Mice were immunized subcutaneously with OVA on day 0 and 14. Starting on the day of immunization, the mice were administered intraperitoneally with EESP at a single dose of 0.25, 0.5, and 1.0 mg, and cyclosporin A (CsA, positive drug) at a single dose of 0.1 mg at intervals of 7 days. On day 28, mitogen- and OVA-induced splenocyte proliferation and OVA-specific antibody level in serum were measured. EESP significantly decreased ConA-, LPS-, and OVA-induced splenocyte proliferation in the OVA-immunized mice at the dose of 1.0 mg. Meanwhile, the OVA-specific serum IgG, IgG1, and IgG2b antibody levels in the OVA-immunized mice were markedly reduced by EESP in a dose-dependent manner. The results suggest that EESP could suppress the cellular and humoral immune response in mice, and deserve further research to be developed as immunosuppressant.

Fracture spacing in layered materials and pattern transition from parallel to polygonal fractures

We perform three-dimensional simulations of fracture growth in a three-layered plate model with an embedded heterogeneous layer under horizontal biaxial stretch (representing stretch from directional to isotropic) by the finite element approach. The fractures develop under a quasistatical, slowly increasing biaxial strain. The material inhomogeneities are accounted for by assigning each element a failure threshold that is defined by a given statistical distribution. A universal scale law of fracture spacing to biaxial strain in terms of principal stress ratio is well demonstrated in a three-dimensional fashion. The numerically obtained fracture patterns show a continuous pattern transition from parallel fractures, laddering fracture to polygonal fractures, which depends strongly on the far-field loading conditions in terms of principal stress ratio lambda = sigma(2)/sigma(1), from uniaxial (lambda = 0), anisotropic (0 < lambda < 1) to isotropic stretch (lambda = 1). We find that, except for further opening of existing fractures after they are well-developed (saturation), new fractures may also initiate and propagate along the interface between layers, which may serve as another mechanism to accommodate additional strain for fracture saturated layers.

Differential gene expression profiling in aggressive bladder transitional cell carcinoma compared to the adjacent microscopically normal urothelium by microdissection-SMART cDNA PCR-SSH

Identifying novel and known genes that are differentially expressed in aggressive bladder transitional cell carcinoma (BTCC) has important implications in understanding the biology of bladder tumorigenesis and developing new diagnostic and therapeutic agents. In this study we identified the differential gene expression profiles comparing tumor to the adjacent microscopically normal mucosa by manual microdissection on frozen sections. The RNAs extracted from microdissected tissues were amplified by SMART cDNA PCR technology to generate forward subtractive cDNA library by suppressive subtractive hybridization (SSH). We obtained 376 positive clones, one hundred clones of aggressive BTCC subtracted cDNA library were selected at random and inserts were reamplified by PCR. After differential screening by reverse dot blotting, 73 positive clones, that contend inserts putatively upregulated in aggressive BTCC, were further analysed by DNA sequencing, GenBank and EST database searching. Sequencing results showed that 66 clones stand for 23 known genes and 7 clones for three new EST (Genbank number: DN236875, DN236874 and DN236873). In conclusion, microdissection-SMART cDNA PCR-SSH allowed for an efficient way to identify aggressive BTCC-specific differential expressed genes that may potentially be involved in the carcinogenesis and/or progression of aggressive BTCC. These differentially expressed genes may be of potential utility as therapeutic and diagnostic targets for aggressive BTCC.

[Estimates of breeding value of Inner Mongolia cashmere goats using animal model BLUP method]

In this study, single trait animal model of best linear unbiased prediction (BLUP) procedures was used to obtain estimates of 3,981 Inner Mongolia cashmere goats' breeding value for body weight and cashmere yield. The data were collected during 1989-1998 at Arbas cashmere goats farm, Etuoke banner, Inner Mongolia. Multiple traits of BLUP were used to get estimates of total breeding values (TBV) of all goats. The model included age and sex-herd-year as fixed effects, and individual additive effect and individual permanent environment as random effects. The selection based on breeding value and phenotypic value was compared. The results showed as following: (1) There was a large difference between weaning weight selection and TBV selection of ram lamb; (2) The difference between phenotypic selection and TBV selection of gimmer hogg reached a significant level (P < 0.01); (3) The difference between phenotypic selection and TBV selection of ram hogg reached a significant level (P < 0.01); (4) Rank correlation between body weight selection and body weight' EBV selection and that between cashmere yield selection and cashmere yield' EBV selection were not significant (P > 0.05). The study concluded precision of individual phenotypic selection was low and animal model BLUP was suitable to select Inner Mongolia cashmere goats. At last, this study gave a series of methods of selecting sires based on objective reality.

Structure of the human serotonin 5-HT4 receptor gene and cloning of a novel 5-HT4 splice variant

Several variants of the serotonin 5-HT4 receptor are known to be produced by alternative splicing. To survey the existence and usage of exons in humans, we cloned the human 5-HT4 gene. Based on sequence analysis seven C-terminal variants (a-g) and one internal splice variant (h) were found. We concentrated in this study on the functional characterization of the novel splice variant h, which leads to the insertion of 14 amino acids into the second extracellular loop of the receptor. The h variant was cloned as a splice combination with the C-terminal b variant; therefore, we call this receptor 5-HT4(hb). This novel receptor variant was expressed transiently in COS-7 cells, and its pharmacological profile was compared with those of the previously cloned 5-HT4(a) and 5-HT4(b) isoforms, with the latter being the primary reference for the h variant. In competition binding experiments using reference 5-HT4 ligands, no significant differences were detected. However, the broadly used 5-HT4 antagonist GR113808 discriminated functionally among the receptor variants investigated. As expected, it was an antagonist on the 5-HT4(a) and 5-HT4(b) variant but showed partial agonistic activity on the 5-HT4(hb) variant. These data emphasize the importance of variations introduced by splicing for receptor pharmacology and may help in the understanding of conflicting results seen with 5-HT4 ligands in different model systems.

[Determination of aflatoxins in peanut by high performance liquid chromatography using immunoaffinity column clean-up and on-line electrochemical derivatization]

A method for the determination of aflatoxin B1, B2, G1 and G2 in peanut by high performance liquid chromatography using immunoaffinity column clean-up and on-line electrochemical derivatization was developed. Sample was extracted with 80% methanol and the extract was passed through the IAC. Aflatoxins were retained by the monoclonal in the IAC and eluted with actonitrile. AFT B1 and G1 were derivatized with on-line electrochemical equipment Kobra Cell. The four toxins can be separated in 13 minutes and the detection limit was 0.1 microgram/kg for each toxin. The method has been applied to the determination of peanut sample. The relative standard deviation was 9.2%-15% and the average recovery of AFT spiked at 0.5-9.0 micrograms/kg levels was in the range of 74.8%-97.3%.

Structural analysis of the mechanism of adenovirus binding to its human cellular receptor, CAR

Binding of virus particles to specific host cell surface receptors is known to be an obligatory step in infection even though the molecular basis for these interactions is not well characterized. The crystal structure of the adenovirus fiber knob domain in complex with domain I of its human cellular receptor, coxsackie and adenovirus receptor (CAR), is presented here. Surface-exposed loops on knob contact one face of CAR, forming a high-affinity complex. Topology mismatches between interacting surfaces create interfacial solvent-filled cavities and channels that may be targets for antiviral drug therapy. The structure identifies key determinants of binding specificity, which may suggest ways to modify the tropism of adenovirus-based gene therapy vectors.

Differentiation of medicinal Codonopsis species from adulterants by polymerase chain reaction-restriction fragment length polymorphism

DNA sequence analysis of rDNA internal transcribed spacer (ITS) and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) were exploited for their applications in differentiating medicinal species Codonopsis pilosula, C. tangshen, C. modesta, and C. nervosa var. macrantha, from two related adulterants Campanumoea javania and Platycodon grandiflorus. The data demonstrated that the rDNA ITSI and ITSII sequences of the four Codonopsis are highly homologous but not identical, and are significantly different from those of the two adulterants. The sequence difference allows effective and reliable differentiation of Codonopsis from the adulterants by PCR-RFLP.

Random primed polymerase chain reaction differentiates Codonopsis pilosula from different localities

DNA fingerprints distinctive among the samples from different localities in China were successfully reproduced for the Chinese herb Dangshen, the roots of CODONOPSIS PILOSULA, (Campanulaceae). Similarity index (S.I.) analysis revealed that C. PILOSULA samples from the same province generated similar DNA fingerprints, while samples of different provinces displayed different DNA fingerprints. This method may be a general and valuable tool for locality authentication of other Chinese herbal medicinal materials.

Alteration of N-acetylglucosaminyltransferases in pancreatic carcinoma

The activities of three N-acetylglucosaminyltransferases (GnT III, GnT IV and GnT V) were determined in 10 samples of pancreatic carcinoma (PCa) and compared with those in 9 samples of normal pancreatic tissue (NP). It was found that the specific activities of GnT III, GnT IV and GnT V increased in all of the PCa samples. GnT III increased most significantly, up to 22.3 fold of normal, GnT IV was elevated 12.3 fold, while GnT V increased only 2.4 fold. The elevation of GnTs in pancreatic carcinoma was consistent with the increase in the number of antenna and bisecting GlcNAc structures in N-glycans of pancreatic ribonuclease (RNase) as assessed by Con A affinity chromatography. Polycytidylate specific RNase from the serum of PCa patients showed the same structural changes as that found in in N-glycans of the RNase from PCa tissue.

The cytochrome P-450 inhibitor cobalt chloride prevents inhibition of renal Na,K-ATPase and redistribution of apical NHE-3 during acute hypertension

Acute systolic arterial hypertension provokes a rapid decrease in proximal tubule sodium reabsorption and diuresis associated with inhibition of renal cortex Na,K-ATPase activity and redistribution of apical membrane Na/H exchanger (NHE-3) to heavier density membranes containing markers of intermicrovillar cleft and endosomes. Because cytochrome P-450-dependent arachidonate metabolites participate in the regulation of renal sodium transport and BP, this study tested the hypothesis that these renal responses to acute hypertension would be prevented if cytochrome P-450 metabolism were inhibited by cobalt chloride (CoCl2). Four groups of rats (n = 4 to 5) were studied: (1) sham-operated; (2) 50 mg of CoCl2/kg subcutaneously for 2 d; (3) acute hypertension by constricting arteries for 5 min; and (4) acute hypertension after CoCl2 treatment as in group 3. Renal cortex was analyzed after sorbitol density gradient fractionation. CoCl2 treatment alone did not significantly affect the rate of urine output, endogenous lithium clearance (an inverse measure of proximal tubule sodium reabsorption), maximal activity of Na,K-ATPase, or subcellular distribution of NHE-3-containing membranes. In non-CoCl2-treated animals, acute hypertension provoked a three- to fourfold increase in urine output and endogenous lithium clearance, 33% inhibition of renal cortex Na,K-ATPase activity, and redistribution of NHE-3 out of the apical membrane peak. In CoCl2-treated animals, acute urine output and endogenous lithium clearance increased only twofold during acute hypertension, there was no inhibition of Na,K-ATPase activity, and there was no redistribution of NHE-3 immunoreactivity to higher density membranes. These findings demonstrate that CoCl2 treatment both attenuates the inhibition of proximal tubule sodium reabsorption and diuresis and abolishes Na,K-ATPase inhibition and NHE-3 redistribution during acute hypertension, evidence that these responses may be mediated by cytochrome P-450 arachidonate metabolites.