Single-crystal growth, structure and thermal transport properties of the metallic antiferromagnet Zintl-phase ß-EuIn2As2.

Zintl-phase materials have attracted significant research interest owing to the interplay of magnetism and strong spin-orbit coupling, providing a prominent material platform for axion electrodynamics. Here, we report the single-crystal growth, structure, magnetic and electrical/thermal transport properties of the antiferromagnet layer Zintl-phase compound ß-EuIn2As2. Importantly, the new layered structure of ß-EuIn2As2, in rhombohedral (R3̄m) symmetry, contains triangular layers of Eu2+ ions. The in-plane resistivity ρ(H, T) measurements reveal metal behavior with an antiferromagnetic (AFM) transition (TN ∼ 23.5 K), which is consistent with the heat capacity Cp(H, T) and magnetic susceptibility χ(H, T) measurements. Negative MR was observed in the temperature range from 2 K to 20 K with a maximum MR ratio of 0.06. Unique 4f7J = S = 7/2 Eu2+ spins were supposed magnetically order along the c-axis. The Seebeck coefficient shows a maximum thermopower |Smax| of about 40 µV K-1. The kink around 23 K in the Seebeck coefficient originates from the effect of the antiferromagnetic phase on the electron band structure, while the pronounced thermal conductivity peak at around 10 K is attributed to the phonon-phonon Umklapp scattering. The results suggest that the Eu2+ spin arrangement plays an important role in the magnetic, electrical, and thermal transport properties in ß-EuIn2As2, which might be helpful for future potential technical applications.

[The application of 3D bioprinting in ophthalmology].

On the basis of 3D printing technology, 3D bioprinting has emerged with great development potential and good prospects in the field of medicine and tissue engineering. With this technique, different types of cells and biomaterials can be precisely incorporated into 3D anatomical structures, achieving tissue substitutes with superior structures or functions. In recent years, great progress has been made in the application of 3D bioprinting in ophthalmology. This article reviews not only the differences between 3D printing and 3D bioprinting, but also the development, types, characteristics, application, and prospects of 3D bioprinting in the production of eye tissue engineering materials.

[A preliminary study on the prevention of hemorrhage after laparoscopic pancreaticoduodenectomy by wrapping gastroduodenal artery stump in the left external liver lobe and the left caudate lobe].

Objective: To investigate the safety and efficacy of embedding the stump of gastroduodenal artery between the left lateral lobe of the liver and the left caudate lobe to prevent bleeding after laparoscopic pancreaticoduodenectomy. Methods: The clinical data of 41 patients who underwent laparoscopic pancreaticoduodenectomy at the second Hospital of Hebei Medical University from October 2021 to April 2022 were analyzed retrospectively.There were 27 males and 14 females, aged (63.0±9.2)years (range: 48 to 78 years), and the body mass index was (24.1±3.2)kg/m2 (range: 15.4 to 31.6 kg/m2). After routine laparoscopic pancreaticoduodenectomy, the stump of gastroduodenal artery was embedded between the left lateral lobe and the left caudate lobe of the liver, and the hepatic parenchyma of the left lateral lobe and the left caudate lobe were sutured with absorbable sutures.The occurrence and recovery of postoperative complications (pancreatic fistula, biliary fistula, postoperative abdominal bleeding, abdominal infection, liver abscess) were observed. Results: All the operations of 41 patients were completed successfully.The operation time was (277.5±52.0) minutes (range: 192 to 360 minutes). The entrapment time of gastroduodenal artery stump was (3.1±0.6) minutes (range: 2.3 to 4.2 minutes), and the intraoperative blood loss (M(IQR)) was 300 (200) ml (range: 50 to 800 ml).The results of ultrasound examination of hepatic artery on the first day after operation showed that the blood flows of hepatic artery were unobstructed.Postoperative pancreatic fistula occurred in 3 cases, including grade B pancreatic fistula in 2 cases (1 case with abdominal infection) and biochemical leakage in 1 case. Three patients with pancreatic fistula were discharged successfully after continuous abdominal drainage. There was no biliary fistula, abdominal bleeding, abdominal infection, liver abscess or postoperative liver dysfunction. Conclusion: The encasement of the gastroduodenal artery stump by the left outer and left caudate lobes of the liver may be an effective way to prevent bleeding from the rupture of the gastroduodenal artery stump after laparoscopic pancreatoduodenectomy, which is easy and safe to perform.

Stover return and nitrogen application affect soil organic carbon and nitrogen in a double-season maize field.

Cultivation techniques have an important influence on grain yield of maize. This experiment investigated the effect of stover return (SR) and different nitrogen (N) application rate on soil organic carbon (SOC) composition, soil nutrient and maize yield. Different nitrogen application rate 100 (N100), 150 (N150), 200 (N200), 250 (N250) or 300 (N300) kg ha-1 applied to the maize field with stover return and without stover return traditional planting (TP) method. Nitrogen application rate and stover return affected the SOC, labile organic carbon (LOC), microbial biomass (MBC), NO3 - -N, NH4 + -N and maize yield. Soil N, soil carbon content and maize yield of SR were all higher than TP. The SOC content of SR and TP were 9.67 and 9.19 g kg-1 , respectively. Nitrogen application was significantly and positively correlated with soil MBC, LOC, SOC, NO3 - -N, NH4 + -N and yield. The maximum values of SOC composition, soil nutrients and maize yield were reached at SR with 250 kg ha-1 . Stover return with application of N 250 kg ha-1 significantly increased the growth attribute and maize yield in subtropical region compared with traditional planting.

The effect of cytoplasmic dynein on the development and functional maintenance of retinal photoreceptor cells.

Cytoplasmic dynein is a multi-subunit complex that includes cytoplasmic dynein-1 (dynein1) and cytoplasmic dynein-2 (dynein2). It participates in various basic cellular processes, including nuclear migration, mitotic spindle organization, chromosome separation during mitosis, and the location and function of numerous intracellular organelles. Retinal photoreceptor cells are terminally differentiated neurons that cannot regenerate and cannot be replaced once lost. It is thus crucial to study their development to facilitate the generation and improvement of photoreceptor disease treatments. The outer segment (OS) of photoreceptor cells is a specific sensory cilium. An increasing number of studies have shown that cytoplasmic dynein plays an essential role in the development of retinal photoreceptor cells. To date, people have done a lot of studies on the various functions of dynein in cells and have a very detailed understanding. However, the role of dynein in retinal photoreceptor cells has not been summarized in detail. This article summarizes the currently available knowledge relating to the effects and mechanisms of cytoplasmic dynein on the development and functional maintenance of retinal photoreceptor cells.

Thermal Dynamics of Charge Density Wave Pinning in ZrTe_{3}.

Impurity pinning has long been discussed to have a profound effect on the dynamics of an incommensurate charge density wave (CDW), which would otherwise slide through the lattice without resistance. Here, we visualize the impurity pinning evolution of the CDW in ZrTe_{3} using the variable temperature scanning tunneling microscopy. At low temperatures, we observe a quasi-1D incommensurate CDW modulation moderately correlated to the impurity positions, indicating a weak impurity pinning. As we raise the sample temperature, the CDW modulation gets progressively weakened and distorted, while the correlation with the impurities becomes stronger. Above the CDW transition temperature, short-range modulations persist with the phase almost all pinned by impurities. The evolution from weak to strong impurity pinning through the CDW transition can be understood as a result of losing phase rigidity.

Urinary microRNAs miR-15b and miR-30a as novel noninvasive biomarkers for gentamicin-induced acute kidney injury.

MicroRNAs serve as potential biomarkers in various pathological models, and are stable and detectable in biofluids. We investigated the urinary microRNA expression profile in a gentamicin-induced acute kidney injury canine model using RNA sequencing. A total of 234 differentially expressed microRNAs were screened after 12 consecutive days of gentamicin administration (P < 0.05). Six candidate microRNAs (miR-15b, -15b-3p, -16, -30a, -30a-3p, and -30c-2-3p) were selected according to a set criterion, and validated by real-time quantitative PCR. The diagnostic values of these six candidate microRNAs were better than the traditional serum biomarkers (all P < 0.05). Further, using receiver operating characteristic curve analysis, we found that miR-15b and -15b-3p were superior to urinary kidney injury molecule-1 (both P < 0.05). Moreover, miR-15b and -30a levels in the urine samples significantly correlated with their respective levels in the kidney tissue samples (r=0.512 and 0.505, respectively, both P < 0.05). Our data concluded that miR-15b and -30a may be promising biomarkers for renal toxicity.

[Clinical characteristics of recurrent appendicitis].

Objective: To analyze clinical characteristics of recurrent appendicitis. Methods: A retrospective cohort study was carried out. Clinical data of patients who underwent appendectomy due to acute appendicitis confirmed by pathology in the Affiliated Hospital of Qingdao University from January 2011 to December 2015 were analyzed retrospectively. Exclusion criteria: (1) age of less than 18 years;(2) chronic appendicitis; (3) periappendiceal abscess; (4) appendiceal mucocele or mucinous neoplasms; (5) appendiceal neuroendocrine tumors or cancers; (6) appendicitis during pregnancy; (7) concurrent AIDS, hematological disease, autoimmune disease, inflammatory bowel disease or advanced cancer; (8) other simultaneous surgery. A total of 373 patients were enrolled the study. These patients were divided into the recurrent group (133 cases) and the first episode group (240 cases) according to the previous history of antibiotic therapy for acute appendicitis. The prevalence of recurrent appendicitis was calculated, and the clinical characteristics were analyzed, including gender, age, comorbidities and preoperative CT images. Results: Of 373 patients, 209 were male and 164 were female, with a median age of 42 (18 to 88) years. Median recurrent time of the recurrent group was 4 (1 to 60) months. Compared to the first episode group, the recurrent group had higher proportion of age <50 years [71.4% (95/133) vs. 57.5% (138/240), χ(2)=7.081, P=0.008], higher proportion of concurrent diabetes [13.5% (18/133) vs. 5.4% (13/240), χ(2)=7.399, P=0.007], shorter onset time [(41.7±13.6) hours vs. (59.4±56.2) hours, t=-3.286, P=0.001], lower proportion of abdominal tension and rebound pain [57.9% (77/133) vs. 66.7% (160/240), χ(2)=5.065, P=0.024], lower score of modified Alvarado score [(5.6±1.9) point vs. (6.1±1.9) point, t=-2.417, P=0.016], lower WBC count [(10.5±4.6) ×10(9)/L vs. (11.5±4.5)×10(9)/L, t=-1.190, P=0.047], higher percentage of lymphocyte [(19.4±14.7)% vs. (16.1±13.3)%, t=2.069, P=0.039]. In the recurrent group, ratio of length of removed appendix ≥7 cm was higher as compared with the first episode group [44.4% (59/133) vs. 32.9% (79/240), χ(2)=4.808, P=0.028], while the ratio of complicated appendicitis was significantly lower [8.3% (11/133) vs. 22.9% (55/240), χ(2)=10.823, P=0.001]. CT images were available in 129 patients, intraluminal appendicoliths was found in 19 of 50 patients (38%) in the recurrent group, while in 16 of 79 patients (20.3%) in the first episode group, and there was statistically significant difference between the two groups (χ(2)=4.880, P=0.027). Conclusions: Clinical characteristics of recurrent acute appendicitis include age less than 50 years, concurrent diabetes, short onset time, less abdominal tension or rebound pain, low modified Alvarado score, low WBC count, high percentage of lymphocyte, appendix length longer than 7 cm, non-complicated appendicitis and intraluminal appendicoliths.

[Retrospective investigation of spontaneous bloody tears: a report of 27 cases].

Objective: To summarize clinical experience on the clinical feature, etiology and treatment of patients with spontaneous bloody tears as the initial symptom. Methods: Retrospective series of case studies. The clinical data and follow-up data of 27 cases of bloody tears as the first symptom in Lacrimal Center of Ophthalmology, the Third Medical Center of Chinese PLA General Hospital from June 2015 to December 2018 were reviewed. The clinical feature, specific cause, diagnosis, treatment and prognosis of these cases were evaluated. Results: A total of 27 cases were collected in this study. The patients were 10 males (37.0%) and 17 females (63.0%), including 21 adults (≥ 18 years old, 77.8%) and 6 minors (<18 years old, 22.2%). There were 22 monocular cases (81.5%) and 5 binocular cases (18.5%). Five cases (18.5%) were bleeding from the eye and other parts of the body, and 22 cases (81.5%) were bleeding only from the eye. There were 19 cases (70.4%) with hematic epiphora and secretions from the punctum, 3 cases (11.1%) with blood-stained tears, and 7 cases (25.9%) with blood-like tears. With regard to etiology, 6 cases (22.2%) were combined with systemic lesions, one of which was granulomatosis with polyangiitis and five of which (<18 years old) were idiopathic bloody tears. Twenty-one cases (77.8%) were local lesions, including 18 cases only involving the lacrimal system, 2 cases only involving the ocular surface, and 1 case involving both the lacrimal system and the ocular surface. Among the 21 cases with local lesions, 5 cases were induced by foreign body, 6 cases were induced by simple inflammation, and 10 cases were induced by tumor including 1 case with conjunctival benign tumor and 9 cases with tumor of the lacrimal system (5 with malignant tumor and 4 with benign tumor). Patients with idiopathic bloody tears received psychological and medical treatment, and interictal discharge was lengthened. One case of granulomatosis with polyangiitis was treated by trans-nasal endoscopic dacryocystorhinostomy. With the recurrence of granulomatosis and polyangiitis, bloody tears recurred after surgery. One patient with conjunctival hemangioma was untreated. Lesions in the lacrimal duct system were removed and dacryocystorhinostomy was performed. In this study, 2 patients (1 with small cell neuroendocrine carcinoma and 1 with adenoid cystic adenocarcinoma) died and the other had a good prognosis. Conclusions: Among the cases of bloody tears, adults and local lesions are more common. Most of the lesions are located in the lacrimal system and are tumors. The main treatment is to remove the lesions, and if necessary, to expand the resection and reconstruct the lacrimal duct. Idiopathic bloody tears occur in minors, who are gave psychotherapy and necessary medical treatment. (Chin J Ophthalmol, 2020, 56: 53-58).

Photosynthetic characteristics of summer maize under different planting patterns and the responses to nitrogen application of previous crop / Características fotossintéticas do milho verão sob diferentes padrões de plantio e as respostas à aplicação de nitrogênio da cultura anterior

Maize (Zea mays L.) is one of the most important grain crops in the North China Plain. Management practices affect the photosynthetic characteristics and the production of summer maize. This two-year (2014-2015) study examined the effects of different planting patterns and the application of nitrogen to previous winter wheat (Triticum aestivum L.) on the photosynthetic characteristics, yield and radiation use efficiency (RUE) of summer maize. Field experiments used a two-factor split-plot design with three replicates at Taian, Shandong Province, China (36°09' N, 117°09' E). The experiments involved two planting patterns(ridge planting, RP; and uniform row planting, UR) and two nitrogen application levels of previous winter wheat (N1, 112.50 kg ha-1; N2, 225.00 kg ha-1). The results indicated that the application of nitrogen on previous crop and ridge planting of the following crop had significant effects on the photosynthetic characteristics and yields of summer maize. Compared with UR, this study found that RP increased the chlorophyll content index (CCI), leaf area index (LAI), net photosynthetic rate (Pn), dry matter (DM), yield and grain RUE by 4.1%, 6.3%, 5.2%, 6.4%, 8.9% and 9.4%, respectively. The CCI, LAI, Pn, yield, and grain RUE of N2 were 9.7%, 3.3%, 3.7%, 10.0% and 10.1% higher than those of N1, respectively. RP combined with the application of nitrogen on previous crop of winter wheat could increase the CCI, LAI, Pn, DM, ultimately increasing the grain yield and RUE of the following summer's maize. It was concluded that previous crop nitrogen application and RP pattern treatment resulted in optimal cropping conditions for the North China plain.

O milho (Zea mays L.) é uma das culturas de grãos mais importantes da Planície do Norte da China. Práticas de manejo afetam as características fotossintéticas e a produção do milho verão. Este estudo de dois anos (2014-2015) examinou os efeitos de diferentes padrões de plantio e a aplicação de nitrogênio ao trigo de inverno anterior (Triticum aestivum L.) sobre as características fotossintéticas, produtividade e eficiência de uso de radiação (RUE) do milho verão. Experimentos de campo usaram um delineamento em parcelas subdivididas de dois fatores com três repetições em Taian, província de Shandong, China (36°09' N, 117°09' E). Os experimentos envolveram dois padrões de plantio (ridge planting, RP; e uniform row planting, UR) e dois níveis de aplicação de nitrogênio do trigo de inverno anterior (N1, 112,50 kg ha-1; N2, 225,00 kg ha-1). Os resultados indicaram que a aplicação de nitrogênio na cultura anterior e no plantio RP da cultura seguinte teve efeitos significativos nas características fotossintéticas e na produtividade do milho verão. Comparado com o plantio UR, este estudo concluiu que RP aumentou o índice de conteúdo de clorofila (CCI), índice de área foliar (LAI), taxa fotossintética líquida (Pn), matéria seca (DM), produtividade e RUE de grãos em 4,1%, 6,4%, 5,2%, 6,4%, 8,9% e 9,4%, respectivamente. Os valores de CCI, LAI, Pn, produtividade e RUE de N2 foram 9,7%, 3,3%, 3,7%, 10,0% e 10,1% superiores aos de N1, respectivamente. RP combinada com a aplicação de nitrogênio na safra anterior de trigo de inverno poderia aumentar os valores de CCI, LAI, Pn, DM, aumentando o rendimento de grãos e RUE do milho do verão seguinte. Concluiu-se que a aplicação prévia de nitrogênio na colheita e o tratamento com padrão RP resultaram em condições ótimas de cultivo para a planície do norte da China.

Submucosal tunneling endoscopic resection using methylene-blue guidance for cardial subepithelial tumors originating from the muscularis propria layer.

Submucosal tunneling endoscopic resection (STER) of subepithelial tumors (SETs) originating from the muscularis propria (MP) layer in the cardia is rarely performed due to the difficulty of creating a submucosal tunnel for resection. The aim of this study is to evaluate the feasibility of STER using methylene-blue guidance for SETs originating from the MP layer in the cardia. From January 2012 to December 2014, 56 patients with SETs originating from the MP layer in the cardia were treated with STER using methylene-blue guidance. The complete resection rate and adverse event rate were the main outcome measurements. Successful complete resection by STER was achieved in all 56 cases (100%). The median size of the tumor was 1.8 cm. Nine patients (15.3%) had adverse events including subcutaneous emphysema, pneumoperitoneum, pneumothorax, and pleural effusion. These nine patients recovered successfully after conservative treatment without endoscopic or surgical intervention. No residual or recurrent tumors were detected in any patient during the follow-up period (median, 25 months). The adverse event rate was significantly higher for tumors originating in the deeper MP layers (46.7%) than in the superficial MP layers (4.9%) (P < 0.05), differed significantly according to tumor size (5.4% for tumors < 2.0 cm vs. 36.8% for tumors ≥ 2.0 cm; P < 0.05), and also differed significantly in relation to the tumor growth pattern (4.1% for the intraluminal growth vs. 100% for the extraluminal growth; P < 0.001). STER using methylene-blue guidance appears to be a feasible method for removing SETs originating from the MP layer in the cardia.

Enrichment of regulatory T-cells in blood of patients with multidrug-resistant tuberculosis.

OBJECTIVE: To measure the percentage of regulatory T-cells (Treg) and the expression of signalling molecules in these cells from the peripheral blood of patients with multidrug-resistant tuberculosis (MDR-TB). DESIGN: Patients with drug-susceptible tuberculosis (S-TB), MDR-TB and healthy controls (HCs) were recruited into the study. Levels of CD4(+)CD25(+)Foxp3(+) Treg cells from peripheral blood, and programmed death-1 (PD-1), cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) and inducible costimulatory (ICOS) molecule expression in the cells were measured using flow cytometry. Suppression mediated by Treg cells was assessed in carboxyfluorescein succinimidyl ester (CFSE) based suppression assays with autologous CD4(+)CD25(-) T-effector (Teff) cells. RESULTS: Presence of Mycobacterium tuberculosis resulted in a higher proportion of Treg cells in S-TB patients than in HCs, and even higher levels in MDR-TB patients. Moreover, Treg cells in MDR-TB patients constitutively expressed high-level PD-1, CTLA-4 and ICOS. In addition, when cultured with activated CD4(+)CD25(-) Teff cells, Treg cells potently suppressed proliferation of Teff cells. CONCLUSIONS: The high level of Treg cells found in the peripheral blood of tuberculosis patients may partly explain the poor immune response against M. tuberculosis, and could be a marker of MDR-TB.

Platelet-targeted microbubbles inhibit re-occlusion after thrombolysis with transcutaneous ultrasound and microbubbles.

Microbubbles (MBs) can augment the acoustic cavitation' (US), thereby facilitating the thrombolysis of external ultrasound. But we observed re-thrombosis after successful thrombolysis by MBs and transcutaneous ultrasound in an endothelium injury model. This study was designed to explore whether platelet-targeted MBs can prevent the reformation of thrombi. Arterial injury was induced in canine femoral arteries with balloon, and the arteries were completely thrombotically occluded. The arteries were treated with intra-arterial MBs or platelet-targeted MBs (TMB) and transcutaneous low frequency ultrasound (LFUS) to achieve complete thrombolysis. The arterial flow was monitored with angiogram for 4h following treatment. Results showed that both MBs and TMBs produced successful dissolution of clots in the presence of ultrasound. The re-occlusion began to occur 1h after thrombolysis in MB/LFUS treatment, and 7 of 8 arteries were re-occluded within 3h. Most of the arteries (7 of 8) in the TMB/LFUS group remained patent for 4h following treatment. The flow tended to decrease after thrombolysis in MB/LFUS treatment. These results indicated that platelet-targeted microbubbles were beneficial in preventing re-thrombosis in vivo and microbubbles served as good carrier of thrombolytic and anticoagulation drugs.

Water and phosphorus content affect PAH dissipation in spiked soil planted with mycorrhizal alfalfa and tall fescue.

Polycyclic aromatic hydrocarbon (PAH) dissipation efficiency can be increased in the plant rhizosphere, but may be affected by various environmental factors. We investigated the effects of the watering regime and phosphorus concentration on PAH dissipation in the rhizosphere of mycorrhizal plants in a pot experiment. Two plant species, alfalfa (Medicago sativa) and tall fescue (Festuca arundinacea), were co-cultured and inoculated with an arbuscular mycorrhizal (AM) fungus (Glomus intraradices) in PAH (phenanthrene (PHE)=500 mg kg(-1), pyrene (PYR)=500 mg kg(-1), dibenzo(a,h)anthracene (DBA)=65 mg kg(-1)) spiked agricultural soil for 6 weeks. Treatments with different phosphorus concentrations and watering regimes were compared. The PHE dissipation reached 90% in all treatments and was not affected by the treatments. The major finding was the significant positive impact of mycorrhizal plants on the dissipation of high molecular weight PAH (DBA) in high-water low-phosphorus treatment. Such an effect was not observed in high-water high-phosphorus and low-water low-phosphorus treatments, where AM colonization was very low. A positive linear relationship was detected between PYR dissipation and the percentage of Gram-positive PAH-ring hydroxylating dioxygenase genes in high-water high-phosphorus treatments, but not in the other two treatments with lower phosphorus concentrations and water contents. Such results indicated that the phosphorus and water regime were important parameters for the dissipation of HMW-PAH.

Prediction of protein structure class by coupling improved genetic algorithm and support vector machine.

Structural class characterizes the overall folding type of a protein or its domain. Most of the existing methods for determining the structural class of a protein are based on a group of features that only possesses a kind of discriminative information for the prediction of protein structure class. However, different types of discriminative information associated with primary sequence have been completely missed, which undoubtedly has reduced the success rate of prediction. We present a novel method for the prediction of protein structure class by coupling the improved genetic algorithm (GA) with the support vector machine (SVM). This improved GA was applied to the selection of an optimized feature subset and the optimization of SVM parameters. Jackknife tests on the working datasets indicated that the prediction accuracies for the different classes were in the range of 97.8-100% with an overall accuracy of 99.5%. The results indicate that the approach has a high potential to become a useful tool in bioinformatics.

Improved prediction of subcellular location for apoptosis proteins by the dual-layer support vector machine.

Apoptosis proteins play an important role in the development and homeostasis of an organism. The accurate prediction of subcellular location for apoptosis proteins is very helpful for understanding the mechanism of apoptosis and their biological functions. However, most of the existing predictive methods are designed by utilizing a single classifier, which would limit the further improvement of their performances. In this paper, a novel predictive method, which is essentially a multi-classifier system, has been proposed by combing a dual-layer support vector machine (SVM) with multiple compositions including amino acid composition (AAC), dipeptide composition (DPC) and amphiphilic pseudo amino acid composition (Am-Pse-AAC). As a demonstration, the predictive performance of our method was evaluated on two datasets of apoptosis proteins, involving the standard dataset ZD98 generated by Zhou and Doctor, and a larger dataset ZW225 generated by Zhang et al. With the jackknife test, the overall accuracies of our method on the two datasets reach 94.90% and 88.44%, respectively. The promising results indicate that our method can be a complementary tool for the prediction of subcellular location.

Influence of guanidine on proteinase K resistance in vitro and infectivity of scrapie prion protein PrP(Sc).

As the scrapie prion protein PrP(Sc) is rich in beta-sheets it aggregates into prion rods, which show infectivity and proteinase K (PK) resistance. Consequently, dissociation of prion rods and breakdown of beta-sheets in PrP(Sc) by denaturation results in loss of both infectivity and PK-sensitivity. In this study, the effects of guanidine (Gdn), which solubilizes and denatures proteins by breaking down their higher structure, on the solubility, the PK-resistance in vitro and the infectivity of PrP(Sc) of scrapie strain 263K was examined. The infectivity was assayed by intracerebral inoculation into hamsters. Brain tissues of scrapie-infected hamsters were used for preparation of homogenates and crude extracts of PrP(Sc). A treatment of PrP(Sc) with Gdn enhanced its PK-sensitivity in a dose-dependent manner. The PK-resistance in vitro of PrP(Sc) denatured with lower concentrations of Gdn (<2.5 mol/l) could partially resume by renaturation. Gdn markedly reduced or, at higher concentrations, even destroyed the infectivity of PrP(Sc). On the other hand, the infectivity of PrP(Sc) inactivated by denaturation could be partially restored by renaturation. These results confirmed our assumption that all the alternations in the PK-resistance and the infectivity of PrP(Sc) caused by Gdn resulted from changes in its higher structure. However, it should be emphasized that a complete loss of PK-resistance of PrP(Sc) may not necessarily mean its full non-infectivity.

Applied anatomy of the V-shaped fibular osteomyocutaneous flap in reconstruction of the hindfoot.

To establish the applied anatomy of the V-shaped fibular osteomyocutaneous flap pedicled on the peroneal vessels, cadaver dissections were made in 60 lower limbs and 40 calcanei were examined to sum up the features of calcaneal biomechanics on the stability of the foot and the blood supply of the fibular osteomyocutaneous flap. There were four anastomoses and large communicating branches between the lower segment of the peroneal artery and the anterior and posterior tibial arteries. The flap was well supplied by a retrograde circulation through these anastomoses. A suitable length of pedicle was 20 cm. In the sagittal section of the calcaneus passing through the center of the articular surface for the cuboid bone, the arrangement of the trabeculae formed a triangular zone. The V-shaped flap corresponds nicely with the calculated lines of stress evoked by the weight of the body. The procedure may provide a new method for hindfoot reconstruction. This flap meets the criteria outlined for composite tissue reconstruction of defects of the extremities and biomechanics of the hindfoot, especially for calcaneal and cuboid defects.

A molecular switch for specific stimulation of the BKCa channel by cGMP and cAMP kinase.

The cGMP and the cAMP pathways control smooth muscle tone by regulation of BK(Ca) (BK) channel activity. BK channels show considerable diversity and plasticity in their regulation by cyclic nucleotide-dependent protein kinases. The underlying molecular mechanisms are unclear but may involve expression of splice variants of the BK channel alpha subunit. Three isoforms, BK(A), BK(B), and BK(C), which were cloned from tracheal smooth muscle, differed only in their C terminus. When expressed in HEK293 cells, cGMP kinase (cGK) but not cAMP kinase (cAK) stimulated the activity of BK(A) and BK(B) by shifting the voltage dependence of the channel to more negative potentials. In contrast, BK(C) was exclusively stimulated by cAK. BK(C) lacks a C-terminal tandem phosphorylation motif for protein kinase C (PKC) with Ser(1151) and Ser(1154). Mutation of this motif in BK(A) switched channel regulation from cGK to cAK. Furthermore, inhibition of PKC in excised patches from cells expressing BK(A) abolished the stimulatory effect of cGK but allowed channel stimulation by cAK. cAK and cGK phosphorylated the channel at different sites. Thus, phosphorylation/dephosphorylation by PKC determines whether the BK channel is stimulated by cGK or cAK. The molecular mechanisms may be relevant for smooth muscle relaxation by cAMP and cGMP.