[Efficacy and outcome of transcatheter closure of patent foramen ovale in patients with cryptogenic stroke]

Objective: To investigate the efficacy and outcome of transcatheter patent foramen ovale (PFO) closure in patients with cryptogenic stroke (CS). Methods: Sixty consecutive patients with cryptogenic stroke who undertook transcatheter PFO closure between May 2015 and September 2017 in Beijing Tiantan Hospital were enrolled in this prospective study.Transcranial Doppler (TCD) bubble test was performed and right-left shunt(RLS) was confirmed in all patients.Closure success rate,effective closure rate, complications, recurrence of ischemic stroke and new onset atrial fibrillation were evaluated. Results: A total of 60 patients (42 male,age range 24-68 (47±11)years) were included in the study.PFO size (motionless state) was (1.6±0.6)mm.RLS before closure was graded and 11 patients had moderate RLS and 48 patients had large RLS (include 41 patients who experienced shower or curtain effect).Closure success rate was 100% (60/60).No severe complications were observed.At 6 months,45 patients completed TCD bubble test.Of these, 4 patients suffered from moderate to large residual and thus effective closure rate was 91%(41/45).The mean follow-up period was 2-29 (median 12) months. During the follow-up, only 1 patient experienced recurrent cerebral infarction.New onset atrial fibrillation was not detected. Conclusion: Transcatheter PFO closure is effective,safe and related with a good outcome in reduction of recurrent CS for patients with PFO.

[Comparison of different massive parallel sequencing platforms for mutation profiling in formalin-fixed and paraffin-embedded samples]

Objective: To compare the performance of Miseq and Ion Torrent PGM platforms and library construction method for next-generation sequencing (NGS) technology for formalin-fixed and paraffin-embedded (FFPE) samples. Methods: A total of 204 FFPE cancer samples including 100 non-small cell lung cancers at the First Affiliated Hospital of Zhejiang University, and 104 colorectal cancers at West China Hospital of Sichuan University were retrospectively selected from January 2013 to December 2016. By using the same samples, DNA was extracted, and the same amount of DNA was used for library construction with the same kit, and sequenced on Miseq and Ion Torrent PGM respectively, after passing the quality control. Any discordant mutations between two platforms were validated by amplified refractory mutation system-polymerase chain reaction (ARMS-PCR) method and Sanger sequencing. Results: A total of 204 FFPE samples were included and 197 samples were successfully analyzed by both platforms. The number of reads generated by the samples on Miseq platform sequencing was higher than PGM platform (median 391 634 vs. 298 030, P<0.01). Alignment with human reference genome showed that the mapping rate of Miseq platform was higher than PGM platform (median 100.0% vs. 99.7%, P<0.01). The median sequence depth of samples on Miseq was higher than PGM platform (median 853× vs. 698×, P<0.01). A total of 236 mutations were detected by two platforms, of which 221 were detected on both platforms, with a 93.6% concordance. Miseq platform detected 11 mutations not detected on PGM platform, while PGM platform detected 4 more mutations not detected on Miseq platform. With validation by ARMS-PCR and Sanger sequencing, Miseq platform was more reliable for low-frequency mutations. The main reasons for the discordant mutations between two platforms were that mutation frequency on undetected platform was lower than mutation reporting range (5%) and FFPE samples were stored for a long time. Conclusions: Compared with PGM, Miseq platform shows higher sequencing quality in terms of the number of reads, alignment results and coverage depth, and the test results are more reliable. In clinical practice, the appropriate platform should be chosen based on sample size and actual throughput requirements to aid in the molecular characterization of tumors.

[The association of lipid profile and bleeding in patients with minor stroke or transient ischemic attack on antiplatelet therapy: subgroup analysis of CHANCE]

Objective: Abnormalities of lipid profile were considered as risk factors of hemorrhage after ischemic stroke. We aimed to determine the relationship between lipid levels and bleeding in minor stroke or transient ischemic attack (TIA) patients receiving antiplatelet therapy. Methods: Serum total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol and triglyceride were tested in a subgroup of 3 044 consecutive patients from Clopidogrel in High-risk patients with Acute Non-disabling Cerebrovascular Events (CHANCE) trial. Patients were randomized to clopidogrel plus aspirin group or single aspirin group. The primary endpoint was any bleeding within 90 days. The secondary endpoint was severe bleeding according to the Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries (GUSTO) definition. Cox proportional hazards models were used to assess the associations of lipid levels and outcomes. Results: A total of 59 (1.9%) bleeding events occurred at 90 days. High-density lipoprotein cholesterol (adjusted HR=2.16; 95%CI 1.17-4.00, P=0.014) and age (adjusted HR=1.04; 95%CI 1.01-1.06, P=0.006) were significantly associated with any bleeding. High-density lipoprotein cholesterol was also associated with severe bleeding (adjusted HR=3.05; 95%CI 1.39-6.68, per 1 mmol/L increase). No correlations between outcomes and levels of total cholesterol, low-density lipoprotein cholesterol and triglyceride were found. There was no interaction of any lipid component level with randomized antiplatelet therapy. Conclusions: Elevated high-density lipoprotein cholesterol is independently associated with any bleeding and severe bleeding in the patients with acute minor stroke or high-risk TIA on antiplatelet therapy.

[Feasibility of amplicon-based targeted next-generation sequencing of colorectal cancer in endoscopic biopsies]

Objective: To investigate whether small endoscopic biopsies of colorectal cancer were sufficient for quality and accurate mutational analysis by amplicon-based next-generation sequencing (NGS). Methods: By using an amplicon-based targeted NGS panel for mutational detection on Illumina Miseq platform, a total of 109 formalin-fixed and paraffin-embedded (FFPE) endoscopic biopsies of colorectal cancer were retrospectively selected, based on specific histopathologic criteria, from January 2012 to June 2016 at West China Hospital of Sichuan University and Peking University Third Hospital. Twelve of these biopsies had corresponding FFPE surgical resection specimens. Quality control parameters of NGS testing were analyzed and NGS results were confirmed by other methods. Mutation calls of the 12 paired endoscopic biopsies and surgical resections were compared. Results: Of the endoscopic biopsy specimens, 97.2% (106/109) had sufficient DNA and qualified sequencing library. NGS generated excellent sequencing data, with a median of 848× for median read depth and 95.7% for uniformity. The success rate of NGS was 95.4% (104/109). Conventional methods confirmed the results of NGS for KRAS and BRAF, and the concordance rate was 100.0%. The clinically actionable mutations detected in the 12 paired endoscopic biopsies and surgical resections were concordant. Conclusion: FFPE endoscopic biopsies of colorectal cancer is suitable for targeted NGS, providing quality sequencing data and accurate mutational information to guide targeted therapy.

Multiple strains and polar states in PbZr0.52Ti0.48O3/PbTiO3 superlattices revealed by aberration-corrected HAADF-STEM imaging

Tuning multiple strain and polar states of ferroelectrics by using strain engineering is an essential approach for designing multifunctional electric devices such as multiple state memories. However, integrating multiple strain states is still a challenge, and in addition, revealing such strains and the resultant polar behaviors on the atomic level remains difficult. In this work we prepare PbZr_0.52Ti_0.48O₃/PbTiO₃ (PZT/PTO) superlattices on SrRuO₃-buffered SrTiO₃(001) substrates. Aberration-corrected high angle annular dark field scanning transmission electron microscopy (HAADF-STEM) reveals that the superlattice is coherent in both c (out-of-plane polar direction) and a (in-plane polar direction) domains. We find that the strain states of both PZT and PTO in c and a domains are variant, leading to four special strain states. For example, the tetragonality for PTO in c and a domains is 1.061 and 1.045, respectively. In contrast, PZT in c domains displays a tetragonality as giant as 1.107, which corresponds to 110 µC cm^-2 spontaneous polarization, much larger than the bulk PZT; while PZT in a domains exhibits 1.010 tetragonality with about 70 µC cm^-2 polarization. This study reveals a practical way to integrate multiple strain states and enhanced polarizations in ferroelectric films, which could be used as multifunctional electric elements.

[Sleep quality analysis in patients with unilateral idiopathic sudden sensorineural hearing loss]

Objective:To analyze the characteristics of sleep quality and its correlation with the clinical features and hearing curative effects in patients with unilateral idiopathic sudden sensorineural hearing loss (ISSHL). Method:Pittsburgh sleep quality index (PSQI) was applied to evaluate the sleep quality of unilateral ISSHL patients in our department. Patient group is divided into poor sleep quality subgroup (total PSQI score>7 points) and normal sleep subgroup (total PSQI score≤7 points). The differences of Patient group and two subgroups between hearing curative effect in the 30 days after treatment and sleep quality scores were compared and analyzed. Questionnaire survey was applied to control group, which contained 70 healthy people with normal hearing level and age matched. Result:A total of 75 cases were collected. To compare with control group, there were statistical difference in the scores of subjective sleep quality, habitual sleep efficiency, sleep disturbance and PSQI before treatment and in the score of habitual sleep efficiency after the treatment for 30 d (P<0.05). The sleep quality between poor sleep quality subgroup and normal sleep subgroup, total therapeutic effect after treatment for 30 d was no significant difference (P>0.05). The proportion for poor sleep quality were no statistically significant differences in the different efficacy of two subgroups (P>0.05). Two subgroups before treatment, in addition to sleep duration, there were statistically significant in all the sleep quality dimensions (P<0.05); after treatment for 30 d, in addition to subjective sleep quality, sleep duration, all have statistical difference (P<0.05). The poor sleep quality subgroup in the case group compared before and after treatment for 30 d, there was statistically significant in subjective sleep quality (P<0.05). The sleep disturbance before treatment, the sleep duration and PSQI scores after treatment for 30 d were associated with clinical features in patients with unilateral ISSHL (P<0.05). Conclusion:The sleep quality of patients with Unilateral SSNHL was significantly lower than that of normal hearing patients, the sleep quality had no significant effect on the general efficacy of unilateral SSNHL, but some sleep quality dimensions are associated with the clinical features before and after treatment.

Topological nature of the node-arc semimetal PtSn4 probed by de Haas-van Alphen quantum oscillations

Dirac node arc semimetal state is a new topological quantum state which is proposed to exist in PtSn₄ (Wu et al 2016 Dirac node arcs in PtSn₄ Nat. Phys. 12 667-71). We present a systematic de Haas-van Alphen quantum oscillation study on this compound. Two intriguing oscillation branches, i.e. F ₁ and F ₂, are detected in the fast Fourier transformation spectra, both of which are characterized to possess tiny effective mass and ultrahigh quantum mobility. And the F ₂ branch exhibits an angle-dependent nontrivial Berry phase. The features are consistent with the existence of the node arc semimetal state and shed new light on its complicated Fermi surfaces and topological nature.

Postoperative radiotherapy is dispensable for OSCC patients with micrometastases in lymph nodes

Lymph node metastasis is a decisive factor for performing postoperative radiotherapy for oral squamous cell carcinoma (OSCC). However, whether OSCC patients with only micrometastasis need postoperative radiotherapy is unclear. In this study, OSCC patients (n = 311) with negative (n = 247), only micrometastasis (n = 44) and macrometastasis (n = 20) were detected and selected by HE staining. Micrometastasis was re-assessed using immunohistochemical staining of cytokeratin (CK) in HE-negative patients to find out the false negative cases. The results indicated that, among the negative lymph node cases (n = 247), the positive rate of CK was 4.94% (n = 12). Besides, the clinical features of the primary tumor in relation to the only micrometastatic status and the value of the postoperative radiotherapy on the only micrometastasis patients were evaluated. Patients with only micrometastasis had higher T stage and inferior worst pattern of invasion (WPOI) than patients without micrometastasis, but they had longer overall survival (OS), metastasis-free survival (MFS), and disease-free survival (DFS) than macrometastasis patients. However, the survival time of only micrometastasis patients with or without postoperative radiotherapy was comparable, even in patients with inferior WPOI. Radiotherapy, however, may only benefit patients with IV/V levels of micrometastasis. These data indicated that postoperative radiotherapy is dispensable for only micrometastasis OSCC patients.

[Association between maternal body height and risk of preterm birth]

Objective: To investigate the association between maternal body height and risk of preterm birth. Methods: A total of 11 311 pregnant women who gave birth of live singletons were recruited from the Healthy Baby Cohort Study in Hubei province, China from September 2012 to October 2014. Finally 11 070 pregnant women were selected as study subjects. Data were collected by using questionnaires, their prenatal care records and medical records. The women were divided into 4 groups according to the quartiles distribution (<158 cm, 158- cm, 160- cm, and >164 cm). Gestational age was estimated according to maternal last menstrual time. Preterm birth was defined as delivering a live singleton infant at 28-37 weeks' gestational age. Logistic regression was used to calculate the odds ratios (OR) and 95% confidence intervals (CI) for the association between body height and preterm birth. Results: Among the 11 070 pregnant women, the incidence of preterm birth was 5.9%. Logistic regression analysis indicated that women in group with body height <158 cm had 46% (OR=1.46, 95%CI: 1.16-1.83) higher risk of giving preterm birth than those in group with body height >164 cm after adjustment for potential confounders. Every 1- cm increase in body height was associated with 3% lower risk of preterm birth (OR=0.97, 95%CI: 0.95-0.99). Conclusion: Shorter body height was a risk factor for preterm birth. It is necessary to strengthen the monitoring in pregnant women with short body height to reduce the risk of preterm birth.

Giant gastrointestinal stromal tumour of the stomach: a case report with surgical treatment

We report a case of giant gastrointestinal stromal tumour of the stomach in a 71-year-old woman, with emphasis on its going through surgical resection. The physical examination and radiological findings revealed that a giant mass occupied most of the abdominal cavity. The patient underwent an en-block resection of the mass, partial resection of the distal stomach and Billroth II gastrojejunostomy. The pathological diagnosis was gastrointestinal stromal tumour. The patient had a long-term disease-free survival. We emphasise that complete surgical resection is the only effective radical treatment approach for giant gastrointestinal stroma of the stomach. In some cases, we still have the opportunity for resection of these tumours because of their expansive growth, even though the lesions are very large.

Novel screening strategy reveals a potent Bacillus antagonist capable of mitigating wheat take-all disease caused by Gaeumannomyces graminis var. tritici

Take-all is a severe root disease of wheat worldwide that is caused by the soilborne fungal pathogen Gaeumannomyces graminis var. tritici (Ggt). In this study, 272 Bacillus isolates were screened for their antifungal activity in vitro to Ggt. Of the 128 strains that demonstrated an antagonistic action, 24 of these exhibited at least three of the four plant growth promotion parameters (i.e. indole acetic acid and siderophore production, inorganic phosphorus solubilization and organic phosphorus solubilization) that were tested in wheat plants. The most effective strain found was Bacillus subtilis Pnf-12; its disease reduction effect reached 69%. Pnf-12 also caused a significant improvement (P < 0·05) in the root and shoot weights of wheat plants, though their root length and shoot height were similar to the noninoculated treatment (P > 0·05). The mechanism for this disease control may be linked to the production of the antifungal lipopeptides surfactin, iturin and fengycin production, all of which were detected in the cell-free supernatant of Pnf-12.

SIGNIFICANCE AND IMPACT OF THE STUDY

Take-all, which is caused by the soilborne fungal pathogen Gaeumannomyces graminis var. tritici (Ggt), is one of the most widespread and devastating root diseases of wheat plants. This study focuses on a novel screening strategy of Bacillus isolates to evaluate their potential biological control capacity for suppressing wheat take-all. The joint assessment of antifungal activities, growth promotion factors and variety of antibiotic synthesis genes, in addition to greenhouse experiments, allowed for the identification and demonstration of the Bacillus isolate Pnf-12 as an effective disease control agent.

[Difference of one year death and stroke recurrence in ischemic stroke patients with anterior and posterior circulation intracranial atherosclerosis]

Objective: To explore the differences of one year death and stroke recurrence between ischemic stroke patients with intracranial atherosclerotic stenosis or occlusion of anterior circulation and those of posterior circulation. Methods: All the patients were from the Chinese Intracranial Atherosclerosis Study (CICAS), between October 2007 and June 2009; patients with extracranial stenosis or occlusion, patients without acute infarction by diffusion weighted image, and patients with intracranial atherosclerosis of both anterior and posterior circulation were excluded.All the enrolled patients were divided into three groups: no significant intracranial atherosclerosis group (n=964), anterior circulation intracranial atherosclerosis group (n=440), posterior circulation intracranial atherosclerosis group (n=233). One year outcome was evaluated by any cause of death and stroke recurrence. Results: Of the 1 637 patients, 30 cases were died and 58 cases had stroke recurrence within one year.Compared with : no significant intracranial atherosclerosis group, adjusted hazard ratio (95% confidence interval) of one-year death for anterior and posterior circulation intracranial atherosclerosis group were 1.349 (0.311-5.851), 4.542 (1.227-16.813), respectively.Adjusted hazard ratio (95% confidence interval) of one year stroke recurrence were 1.663 (0.620-4.460) and 2.464 (0.935-6.493), respectively. Conclusions: Ischemic stroke patients with intracranial atherosclerosis of posterior circulation has higher risk of one year death. One year stroke recurrence risk for patients with intracranial atherosclerosis of anterior and posterior circulation needs to be further evaluated.

[Clinical features and gene mutation analysis of patients with Niemann-Pick disease type C]

Objective: To analyze the clinical manifestations, therapeutic efficacy, prognosis and characteristics of NPC1 mutation in Chinese patients with Niemann-Pick disease type C(NPC). Methods: Ten unrelated Chinese NPC patients were diagnosed by NPC1 mutation analysis from July 2013 to February 2017 in Beijing Tian Tan Hospital of Capital Medical University. Clinical data of 10 cases were analyzed retrospectively which included clinical manifestations, laboratory results and NPC1 gene mutation features, and a series of follow-up were carried out about therapeutic efficacy and prognosis. Results: Ten patients suffering from NPC included 5 males and 5 females, aged from 42 days to 14 years when they presented to Tian Tan Hospital. According to their age of neurological onset, 4 were in early infantile period, 2 in late infantile period, 2 in juvenile periods, and the other 2 cases in neonatal period. They all presented with splenomegaly, 5 of 10 accompanied with hepatomegaly. Two cases of neonatal subtype presented mainly with delayed neonatal cholestatic jaundice and hepatosplenomegaly, accompanied with decreased muscle tone and slight psychomotor retardation. The other 8 cases presented with severe neurological involvement, such as progressive encephalopathy, ataxia and language impairment, 4 with dystonia, 3 with decreased muscle tension, 5 with vertical supranuclear gaze palsy, 5 with gelastic cataplexy, and 4 with epilepsy. Eight of 9 cases presented with foam cells in their bone marrow. Head MRI showed diffuse cerebral atrophy in 8 cases, thin corpus callosum in 2 cases, and brain white matter abnormal signals in 2 cases. Among 10 cases, 18 different mutations of NPC1 allelic genes were identified including 11 reported mutations, 3 novel missense mutations: c. 3683T>C (p.Met1128Thr), c.1926G>C (p.Met642Iie) and c. 3006C>G (p.Phe1002Leu), 2 novel nonsense mutation: c. 1142G>A(p.Trp381Ter ) and c. 3229C>T(p.Arg1077Ter), 1 novel minimal deletion mutation: c. 1385-1386del, and 1 novel intron mutation: c. 1757+ 5G>A. In 5 cases, the symptom of gelastic cataplexy was alleviated by imipramine, and the convulsion was relieved by valproate in 2 cases, by carbamazepine in 1 case at the beginning of seizure. During the 25 (3-66) months of follow-up, 4 cases died, the others' neurological symptoms were deteriorated progressively. Conclusions: The NPC1 gene mutation were high heterozygous in this group, and 7 novel mutations enriched the gene mutation spectrum of NPC1. The neurological manifestations were complicated in patients with NPC, and the symptomatology would be different according to their onset age of neurological symptoms. There might be effective symptomatic treatment for gelastic cataplexy by imipramine and for convulsion by valproate or carbamazepine.

Assessment of the Combined Effect of Plasma Exchange and Plasma Perfusion on Patients with Severe Hepatitis Awaiting Orthotopic Liver Transplantation

To determine if plasma exchange combined with plasma perfusion is a reliable and effective temporary liver support treatment for patients on the waiting list for OLT, we tested this method in 5 patients with end-stage and 3 patients with middle-stage severe hepatitis. Four patients were successfully controlled until a donor liver was available 4 to 13 days later. In contrast, the remaining 4 patients were not adequately controlled by this treatment and experienced aggravated disease progression, dying 3 to 8 days after treatment while still awaiting OLT. Of those 4 patients who received OLT, 2 patients died from multi-organ failure caused by hepatic failure, while the other 2 survived. These findings show that plasma exchange combined with plasma perfusion provides temporary support for some patients on the waiting list for OLT. The ability of patients to successfully bridge to OLT is closely associated with the degree of liver failure, complications, multi-organ failure, and the length of the waiting period for a donor liver.

Designing of metallic nanocrystals embedded in non-stoichiometric perovskite nanomaterial and its surface-electronic characteristics

Engineering of novel functional nanocomposite as like as the metallic nanocrystals supported non-stoichiometric perovskite nanomaterial in controlled parameters (size, shape and ratio of chemical characteristics) is a challengeable task. In this context, we present a facile route to fabricate and study its physicochemical property at real time mode in this report. Nanoscale pure Pb crystals surfaced on non-stoichiometric A-site deficient Pb_1-xTiO_3-y nanoparticle were fabricated when a precursor lead titanate (PbTiO₃) nanoparticle was exposed to an electron beam irradiation (EBI) in a transmission electron microscope (TEM) at ambient temperature. In the state of the art, the chemical states and electronic structure of non-irradiated and irradiated PbTiO₃ were studied by X-ray photoelectron spectroscopy (XPS). Electron bombardment resulted in a new visible feature at low binding energy in the Pb 4f core level, while Ti 2p and O 1s line shape showed slight changes. The Fermi level of the corresponding materials was determined to be 1.65 ± 0.1 eV and 2.05 ± 0.1 eV above the valence band maximum, respectively. The normal, weakly p-type PTO exhibits peculiar n-type feature after EBI process (The Fermi level moves near to the conduction band). A feasible mechanism is proposed involving the electron-stimulated local bond-breaking phenomenon in PbTiO₃.

[Evaluation of the modified test system for children sound localization]

Objective: To evaluate the feasibility of modified test system for sound localization (SL) in children. Methods: Modified system (6 male, 9 female) and traditional method ( 5 male, 5 female) were used for evaluation of minimum audible angle(MAA) and root-mean-square error(RMS) error of 4 to 6 years old children, and the results were compared to verify the accuracy and effectiveness of the modified test system for children sound localization.SPSS 17.0 software was used to analyze the data(t test). Results: (1) Comparison of veracity of modified system and traditional test: when tested at the positive front position using modified system, MAA and RMS error were(3.23±1.00)° and (13.68±5.18)° respectively.When using traditional method, MAA and RMS error were(3.17±0.59)°and (13.96±4.56)° respectively. No statistical differences were found between two groups(t value was 0.16, -0.14, both P>0.05). (2) Comparison of time used were as followed: when using modified system, it was (14.67±1.95) min for MAA, and (6.67±1.35) min for RMS error. When using traditional method, it was (36.30±6.81) min for MAA, and (21.00±3.50) min for RMS error. Time used were significant shorter in modified system than in traditional method (t value was-9.78, -12.37, both P<0.05). Conclusion: Modified test system for children sound localization is useful and reliable in children's horizontal SL test.The time used of modified test system is shorter than that of traditional test system.

Aortic dissection with acute non-st-segment elevation myocardial infarction as the first manifestation

Acute chest pain caused by aortic dissection or acute myocardial infarction (AMI) is one of the most serious medical emergencies and requires very quick differential diagnosis to seize the best time for treatment. Aortic dissection and acute myocardial infarction are manifested with similar symptoms, making it difficult to differentially diagnose these two conditions. The present case was initially misdiagnosed as an acute non-ST-segment elevation myocardial infarction (NSTEMI) with left aortic disease, and then diagnosed by coronary angiography examination as type A aortic dissection (AAD). This case points to the need to collect and analyze as much patient clinical data as possible, including medical history and the results of auxiliary examination which would help to avoid misdiagnosis or treatment delay and reduce mortality among patients with type AAD when they manifest symptoms of chest pain and an ECG pattern of NSTEMI.

Study on the expression of human lysozyme in oviduct bioreactor mediated by recombinant avian adeno-associated virus

Due to its antimicrobial properties and low toxicity, human lysozyme (hLYZ) has broad application in the medical field and as a preservative used by the food industry. However, limited availability hinders its widespread use. Hence, we constructed a recombinant avian adeno-associated virus (rAAAV) that would specifically express hLYZ in the chicken oviduct and harvested hLYZ from the egg whites of laying hens. The oviduct-specific human lysozyme expression cassette flanked by avian adeno-associated virus (AAAV) inverted terminal repeats (ITRs) was subcloned into the modified baculovirus transfer vector pFBX, and then the recombinant baculovirus rBac-ITRLYZ was generated. The recombinant avian adeno-associated virus was produced by co-infecting Sf9 cells with rBac-ITRLYZ and the other 2 baculoviruses containing AAAV functional genes and structural genes, respectively. Electron microscopy and real-time PCR revealed that the recombinant viral particles were generated successfully with a typical AAAV morphology and a high titer. After one intravenous injection of each laying hen with 2 × 1011 viral particles, oviduct-specific expression of recombinant human lysozyme (rhLYZ) was detected by reverse transcription-PCR. The expression level of rhLYZ in the first wk increased to 258 ± 11.5 μg/mL, reached a maximum of 683 ± 16.4 μg/mL at the fifth wk, and then progressively declined during the succeeding 7 wk of the study. Western blotting indicated that the oviduct-expressed rhLYZ had the same molecular weight as the natural enzyme. These results indicate that an efficient and convenient oviduct bioreactor mediated by rAAAV has been established, and it is useful for production of other recombinant proteins.

Giant linear strain gradient with extremely low elastic energy in a perovskite nanostructure array

Although elastic strains, particularly inhomogeneous strains, are able to tune, enhance or create novel properties of some nanoscale functional materials, potential devices dominated by inhomogeneous strains have not been achieved so far. Here we report a fabrication of inhomogeneous strains with a linear gradient as giant as 10⁶ per metre, featuring an extremely lower elastic energy cost compared with a uniformly strained state. The present strain gradient, resulting from the disclinations in the BiFeO₃ nanostructures array grown on LaAlO₃ substrates via a high deposition flux, induces a polarization of several microcoulomb per square centimetre. It leads to a large built-in electric field of several megavoltage per metre, and gives rise to a large enhancement of solar absorption. Our results indicate that it is possible to build up large-scale strain-dominated nanostructures with exotic properties, which in turn could be useful in the development of novel devices for electromechanical and photoelectric applications.

Connexin 43 enhances oxaliplatin cytotoxicity in colorectal cancer cell lines

Oxaliplatin, a platinum-based chemotherapeutic agent, is an important first-line drug in the treatment of colorectal cancers, but drug resistance causes treatment failure. It has been reported that gap junctional communication can enhance the cytotoxicity of platinum drugs.  The gap junction formed of connexin proteins provides a direct pathway for electrical and metabolic cell-cell interaction. The voltage-dependent gating of gap junction allows small hydrophilic molecules and ions to permeate to adjacent cells. Connexin 43 is a diagnostic marker for cancer therapy and the predominant connexin isoform in many cell types. The purpose of this study was to investigate the role of connexin 43 in oxaliplatin activity by using colorectal cancer cell lines. LoVo and HCT116 cell lines were used for analysis. Connexin 43 expression was confirmed by western blot and immunocytochemistry. MTT, western blot, "Parachute" dye-coupling assays and reactive oxygen species measurement were used to detect cytotoxicity and the inhibition of connexin 43 expression induced by oxaliplatin. Results showed that connexin 43 enhanced oxaliplatin cytotoxicity through gap junctional communication function and high concentration of oxaliplatin inhibited connexin 43 expression to counteract its cytotoxicity. This study suggested that connexin 43 could be considered a molecular target of oxaliplatin activity in colorectal cancer.