High-Definition Transcranial Direct Current Stimulation in the Right Ventrolateral Prefrontal Cortex Lengthens Sustained Attention in Virtual Reality.

Due to the current limitations of three-dimensional (3D) simulation graphics technology, mind wandering commonly occurs in virtual reality tasks, which has impeded it being applied more extensively. The right ventrolateral prefrontal cortex (rVLPFC) plays a vital role in executing continuous two-dimensional (2D) mental paradigms, and transcranial direct current stimulation (tDCS) over this cortical region has been shown to successfully modulate sustained 2D attention. Accordingly, we further explored the effects of electrical activation of the rVLPFC on 3D attentional tasks using anodal high-definition (HD)-tDCS. A 3D Go/No-go (GNG) task was developed to compare the after effects of real and sham brain stimulation. Specifically, GNG tasks were periodically interrupted to assess the subjective perception of attentional level, behavioral reactions were tracked and decomposed into an underlying decision cognition process, and electroencephalography data were recorded to calculate event-related potentials (ERPs) in rVLPFC. The p-values statistically indicated that HD-tDCS improved the subjective mentality, led to more cautious decisions, and enhanced neuronal discharging in rVLPFC. Additionally, the neurophysiological P300 ERP component and stimulation being active or sham could effectively predict several objective outcomes. These findings indicate that the comprehensive approach including brain stimulation, 3D mental paradigm, and cross-examined performance could significantly lengthen and robustly compare sustained 3D attention.

Evaluating the Alterations Induced by Virtual Reality in Cerebral Small-World Networks Using Graph Theory Analysis with Electroencephalography.

Virtual reality (VR), a rapidly evolving technology that simulates three-dimensional virtual environments for users, has been proven to activate brain functions. However, the continuous alteration pattern of the functional small-world network in response to comprehensive three-dimensional stimulation rather than realistic two-dimensional media stimuli requires further exploration. Here, we aimed to validate the effect of VR on the pathways and network parameters of a small-world organization and interpret its mechanism of action. Fourteen healthy volunteers were selected to complete missions in an immersive VR game. The changes in the functional network in six different frequency categories were analyzed using graph theory with electroencephalography data measured during the pre-, VR, and post-VR stages. The mutual information matrix revealed that interactions between the frontal and posterior areas and those within the frontal and occipital lobes were strengthened. Subsequently, the betweenness centrality (BC) analysis indicated more robust and extensive pathways among hubs. Furthermore, a specific lateralized channel (O1 or O2) increment in the BC was observed. Moreover, the network parameters improved simultaneously in local segregation, global segregation, and global integration. The overall topological improvements of small-world organizations were in high-frequency bands and exhibited some degree of sustainability.

Design and Micro-Nano Fabrication of a GaAs-Based On-Chip Miniaturized Bandpass Filter with Intertwined Inductors and Circinate Capacitor Using Integrated Passive Device Technology.

In this study, we propose a miniaturized bandpass filter (BPF) developed by combining an approximate circular (36-gon) winding inductor, a circinate capacitor, and five air-bridge structures fabricated on a gallium arsenide (GaAs) substrate using an integrated passive device (IPD) technology. We introduced air-bridge structures into the outer metal wire to improve the capacitance per unit volume while utilizing a miniaturized chip with dimensions 1538 µm × 800 µm (0.029 λ0 × 0.015 λ0) for the BPF. The pattern was designed and optimized by simulating different dimensional parameters, and the group delay and current density are presented. The equivalent circuit was modeled to analysis various parasitic effect. Additionally, we described the GaAs-based micro-nano scale fabrication process to elucidate the proposed IPD technology and the physical structure of the BPF. Measurements were conducted with a center frequency of 1.53 GHz (insertion loss of 0.53 dB) and a 3-dB fractional bandwidth (FBW) of 70.59%. The transmission zero was located at 4.16 GHz with restraint of 35.86 dB. Owing to the benefits from its miniaturized chip size and high performance, the proposed GaAs-based IPD BPF was verified as an excellent device for various S-band applications, such as satellite communication, keyless vehicle locks, wireless headphones, and radar.

Permittivity-Inspired Microwave Resonator-Based Biosensor Based on Integrated Passive Device Technology for Glucose Identification.

In this study, we propose a high-performance resonator-based biosensor for mediator-free glucose identification. The biosensor is characterized by an air-bridge capacitor and fabricated via integrated passive device technology on gallium arsenide (GaAs) substrate. The exterior design of the structure is a spiral inductor with the air-bridge providing a sensitive surface, whereas the internal capacitor improves indicator performance. The sensing relies on repolarization and rearrangement of surface molecules, which are excited by the dropped sample at the microcosmic level, and the resonance performance variation corresponds to the difference in glucose concentration at the macroscopic level. The air-bridge capacitor in the modeled RLC circuit serves as a bio-recognition element to glucose concentration (εglucoseC0), generating resonant frequency shifts at 0.874 GHz and 1.244 GHz for concentrations of 25 mg/dL and 300 mg/dL compared to DI water, respectively. The proposed biosensor exhibits excellent sensitivity at 1.38 MHz per mg/dL with a wide detection range for glucose concentrations of 25-300 mg/dL and a low detection limit of 24.59 mg/dL. Additionally, the frequency shift and concentration are highly linear with a coefficient of determination of 0.98823. The response time is less than 3 s. We performed multiple experiments to verify that the surface morphology reveals no deterioration and chemical binding, thus validating the reusability and reliability of the proposed biosensor.

Fabrication of QFN-Packaged Miniaturized GaAs-Based Bandpass Filter with Intertwined Inductors and Dendritic Capacitor.

This article presents a compact quad flat no-lead (QFN)-packaged second-order bandpass filter (BPF) with intertwined inductors, a dendritic capacitor, and four air-bridge structures, which was fabricated on a gallium arsenide (GaAs) substrate by integrated passive device (IPD) technology. Air-bridge structures were introduced into an approximate octagonal outer metal track to provide a miniaturized chip size of 0.021 × 0.021 λ0 (0.8 × 0.8 mm2) for the BPF. The QFN-packaged GaAs-based bandpass filter was used to protect the device from moisture and achieve good thermal and electrical performances. An equivalent circuit was modeled to analyze the BPF. A description of the manufacturing process is presented to elucidate the physical structure of the IPD-based BPF. Measurements were performed on the proposed single band BPF using a center frequency of 2.21 GHz (return loss of 26.45 dB) and a 3-dB fractional bandwidth (FBW) of 71.94% (insertion loss of 0.38 dB). The transmission zero is located at the 6.38 GHz with a restraint of 30.55 dB. The manufactured IPD-based BPF can play an excellent role in various S-band applications, such as a repeater, satellite communication, and radar, owing to its miniaturized chip size and high performance.

On-Chip Miniaturized Bandpass Filter Using GaAs-Based Integrated Passive Device Technology For L-Band Application.

In this work, a miniaturized bandpass filter (BPF) constructed of two spiral intertwined inductors and a central capacitor, with several interdigital structures, was designed and fabricated using integrated passive device (IPD) technology on a GaAs wafer. Five air-bridge structures were introduced to enhance the mutual inductive effect and form the differential geometry of the outer inductors. In addition, the design of the differential inductor combined with the centrally embedded capacitor results in a compact construction with the overall size of 0.037λ0 × 0.019λ0 (1537.7 × 800 µm2) where λ0 is the wavelength of the central frequency. For the accuracy evolution of the equivalent circuit, the frequency-dependent lumped elements of the proposed BPF was analyzed and modeled through the segment method, mutual inductance approach, and simulated scattering parameters (S-parameters). Afterward, the BPF was fabricated using GaAs-based IPD technology and a 16-step manufacture flow was accounted for in detail. Finally, the fabricated BPF was wire-bonded with Au wires and packaged onto a printed circuit board for radio-frequency performance measurements. The measured results indicate that the implemented BPF possesses a center frequency operating at 2 GHz with the insertion losses of 0.38 dB and the return losses of 40 dB, respectively, and an ultrawide passband was achieved with a 3-dB fraction bandwidth of 72.53%, as well. In addition, a transmission zero is located at 5.32 GHz. Moreover, the variation of the resonant frequency with different inductor turns and metal thicknesses was analyzed through the simulation results, demonstrating good controllability of the proposed BPF.

C-doped ZnO decorated with Au nanoparticles constructed from the metal-organic framework ZIF-8 for photodegradation of organic dyes.

Recently, engineering metal-organic frameworks (MOFs) into metal oxides by solid state thermal decomposition has attracted wide attention for photocatalytic applications. Here, a series of C-doped ZnO materials decorated with Au nanoparticles (Au/C-ZnO) were constructed via controlled pyrolysis of ZIF-8 adsorbing different amounts of HAuCl4·4H2O. In this pyrolysis process, ZIF-8 was transformed into C-doped ZnO according to the EDX and XPS analysis. Meanwhile, HAuCl4·4H2O was transformed into Au nanoparticles that were uniformly dispersed on the surface of C-ZnO as seen in TEM images. The photocatalytic activity of as-prepared catalysts was evaluated by the degradation of methyl orange under UV-vis light irradiation. It was found that the photocatalytic activity of Au/C-ZnO was better than C-ZnO and pure ZnO. Furthermore, Au/C-ZnO exhibited high photocatalytic stability. After three consecutive cycles, there was no noticeable deactivation in the reaction. This unusual photocatalytic activity was attributed to the synergistic effect of C-doping and Au NPs.

The Role of Malic Enzyme on Promoting Total Lipid and Fatty Acid Production in Phaeodactylum tricornutum.

To verify the function of malic enzyme (ME1), the ME1 gene was endogenously overexpressed in Phaeodactylum tricornutum. Overexpression of ME1 increased neutral and total lipid content and significantly increased saturated fatty acids (SFAs) and polyunsaturated fatty acids (PUFAs) in transformants, which varied between 23.19 and 25.32% in SFAs and between 49.02 and 54.04% in PUFAs, respectively. Additionally, increased ME1 activity was accompanied by elevated NADPH content in all three transformants, indicating that increased ME1 activity produced additional NADPH comparing with that of WT. These results indicated that ME1 activity is NADP-dependent and plays an important role in the NADPH levels required for lipid synthesis and fatty acid desaturation in P. tricornutum. Furthermore, our findings suggested that overexpression of endogenous ME1 represents a valid method for boosting neutral-lipid yield in diatom.

Silencing UDP-glucose pyrophosphorylase gene in Phaeodactylum tricornutum affects carbon allocation.

The effects of the suppression of UDP-glucose pyrophosphorylase (UGPase) on chrysolaminaran biosynthesis and carbon allocation were investigated in Phaeodactylum tricornutum. The 69% decrease in UGPase activity was accompanied by a 4.89 fold reduction in Ugp transcript abundance. Inactivation of UGPase in P. tricornutum led to a significant decrease in chrysolaminaran content and an increase in lipid synthesis. These findings suggest that UGPase is a rate-limiting enzyme and may play an important role in chrysolaminarin biosynthesis and carbon allocation. Our results support a theoretical deduction that Ugp is a good candidate for improving lipid synthesis in diatoms.

[Identification of HBx-related integration sites in HBsAg-positive hepatocellular carcinoma biopsy].

To identify the integration sites in the host genome for the hepatitis B virus (HBV)-encoded X protein (HBx) in hepatocellular carcinoma (HCC) biopsies that are positive for hepatitis B surface antigen (HBsAg). HCC biopsies were obtained from six patients that were HBV carriers, as demonstrated by the presence of HBsAg in their serum and sero-negativity for antibody to HBsAg. DNA was extracted from the tissue, fractionated, and circularized. Primers were designed according to the HBx sequence and used to amplify the circularized DNA templates by inverse polymerase chain reaction (IPCR). The amplified DNA fragments were checked by electrophoresis, cloned into the PMD18-T expression vector, and sequenced. Sequence alignment was performed by the Blast algorithms. Seven electrophoresis bands yielded 22 sequencing results, which represented a total of three HBx integration sites in the host genome: 19q12, 2q32.2, 22q12. The 19q12 integration site encompasses the CCNE1 gene, which encodes a G1/S-specific cyclin-E1. HBx-related integration sites exist in HBsAg-positive HCC biopsies. The CCNE1 gene may play a role in the development of HBx-related HCC.

[Clinical observation on influence of vertebral fixation through or across the affected vertebra on vertebral morphology].

OBJECTIVE: To compare the long-term influence of vertebral fixation through or across the affected vertebra on vertebral morphology. METHODS: Clinical data of 48 patients with simple thoracic and lumbar spinal fractures who were admitted between Jan. 2008 and Dec. 2010 were analyzed retrospectively. Among them 36 cases (28 males and 8 females) were fixed through the injured vertebra (group A) and 12 cases (8 males and 4 females) were fixed across the injured vertebra (group B). All patients were followed up for 6-36 months (mean 11.5 months). The vertebral body height, endplate angle and neurofunction were compared between the two groups before surgery, a week after surgery and at the end of the follow-up period. RESULTS: There was no statistically significant difference in vertebral body height,endplate angle and neurofunction before operation between group A and B (P > 0.05). Vertebral body height and endplate angle improved in both groups a week after operation and at the end of the follow-up period as compared with those before operation (P < 0.05), and the efficacy in group B was significantly better than that in group A (P < 0.05). There was no significant difference in neurofunction between the two groups (P > 0.05). CONCLUSION: The fixation method through the injured vertebra had a better reduction effect, more stable fixation, and a better long-term effect on vertebral morphology than that across the injured vertebra in the treatment of thoracolumbar vertebral fractures.

[Effect of Saikosaponins-d on reversing malignant phenotype of HepG2 cells in vitro].

OBJECTIVE: To observe the effect of SSd on reversing the malignant phenotype of HepG2 cells and to investigate its mechanism in order to prove that SSd is a new choice to prevent and treat HCC. METHODS: HepG2 cells were cultured and treated by different concentration (0 mg/L, 2.5 mg/L, 5.0 mg/L, 10.0 mg/L and 20.0 mg/L) of SSd for 24 h, and treated by 10 mg/L of SSd for 0 h, 6 h, 12 h, 24 h, 48 h and 72h respectively. The cell inhibition rates were measured by MTT assay. Then cells were treated by 10 mg/L SSd for 48 hr in experimental group and treated by no SSd as a control, their morphological changes were observed by contrast phase microscope. The concentrations of ALB and AFP in clear supernatant liquid of cells were detected by radio-immunity and chemiluminescence. The cell migration rates were observed by transwell method, the relative expression levels of p27 mRNA were measured by RT-PCR. RESULTS: The inhibitive effect of 10 mg/L SSd was the most significant among different concentrations ( F = 265.06, P less than 0.01). The shape of HepG2 from experimental group turned into small and round, and their volume ratios of nucleus to plasma decreased. ALB in supernatant liquid of HepG2 was higher ( t = 7.83, P less than 0.05, and its AFP was lower ( t = -10.72, P less than 0.01) as compared to control group. Cells migrated were fewer and p27 mRNA expression of HepG2 was higher in experimental group than that in control group (t = 22.00, P less than 0.05). CONCLUSION: SSd could reverse the malignant phenotype of HepG2 cells. It was suggested that the up-regulation of p27 mRNA expression play an important role in the differentiation of HepG2 cells treated by SSd.

Application of trichloroacetic acid-acetone precipitation method for protein extraction in bone tissue / 中国医学科学院学报

<p><b>OBJECTIVE</b>To explore the feasibility and efficiency of extracting protein from bone tissue using trichloroacetic acid (TCA)-acetone precipitation method.</p><p><b>METHODS</b>Hydrochloric acid (HCL) decalcification method and TCA-acetone precipitation method were separately used for bone protein extraction. The efficiencies of these two methods were compared.</p><p><b>RESULTS</b>TCA-acetone precipitation method had significantly higher extraction efficiency. Compared with HCL decalcification method, it had less pollution from bone marrow hematopoietic tissue. Protein band distribution was similar between these two methods.</p><p><b>CONCLUSION</b>TCA-acetone precipitation method is useful for bone proteomics research.</p>

Endobronchial ultrasound-guided transbronchial needle aspiration of undiagnosed mediastinal lymphadenopathy.

BACKGROUND: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) can sample the enlarged mediastinal lymph nodes which are unreachable by conventional bronchoscopy. It is a relatively simple and safe method to see beyond the bronchial tree. We describe and discuss its initial application and our experience. METHODS: From July 2009 to December 2009, 52 patients with undiagnosed enlarged mediastinal lymph nodes were accessed with EBUS-TBNA in the People's Liberation Army General Hospital. Conventional bronchoscopy was performed before EBUS-TBNA, and patients with endobronchial lesions were excluded from this study. Smears fixed in 95% alcohol and histological specimens fixed in formalin were sent to Department of Pathology. RESULTS: EBUS-TBNA was diagnostic in 33 (63%) patients, with diagnosis of lung cancer in 23 patients (14 patients of small cell lung cancer, eight patients with adenocarcinoma, and one patient of squamous carcinoma). Four patients, who had negative EBUS-TBNA results, were later diagnosed with malignancy at thoracotomy. One patient with negative EBUS-TBNA results died of cancer cachexia. The sensitivity, specificity, and positive and negative predictive value of EBUS-TBNA for the diagnosis of neoplastic disease were 85%, 100%, 100%, and 50% respectively. Among the 16 sarcoidosis patients, who were diagnosed by a combination of the clinical and radiological information as well as pathological results obtained by EBUS-TBNA, nine of them had granulomas and benign lymphoid cells detected by EBUS-TBNA. The sensitivity, specificity, and positive and negative predictive value of EBUS-TBNA for the diagnosis of sarcoidosis were 56%, 100%, 100%, and 13%, respectively. Five patients with no definite diagnosis from EBUS-TNBA examination are under close follow-up. CONCLUSIONS: EBUS-TBNA can provide a safe and effective method to sample mediastinal leisions suspected of malignancy. It also adds pathological information needed to make the diagnosis of sarcoidosis.

[Integration sites in HCC biopsy].

OBJECTIVE: To compare the performance of Inverse-PCR, Alu-PCR and Cassette-ligation-mediated PCR (CLM-PCR) in HBV DNA integration sites identification. METHODS: One HCC biopsy was obtained from surgically resected sample. The patient was positive for serum hepatitis B surface antigen (HBsAg). The genomic DNA was purified by the standard phenol/chloroform extraction and ethanol precipitation method. Seperated set of primers were designed to amplify the HBV DNA integration region by means of 3 different PCR methods respectively. The PCR products were analyzed by electrophoresis, then cloned to PMD18-T vector for DNA sequencing. The sequence alignment was performed under Blast software. RESULTS: 7 bands and 22 sequencing results was obtained from IPCR and 3 integration sites was identified. Alu-PCR provided 12 bands and 32 sequencing results, and CLM-PCR showed 12 bands and 4 sequencing results. No integration site was identified from the latter two. CONCLUSION: IPCR compared with another two methods showed a reliable capacity in HBV DNA integration site identification.

A cyclic hexanuclear heterometalladithiolene cluster [{(Cp*Rh)2Mo(mu-CO)2(CO)}2(S2C6H2S2)2] with two pi-conjugated S2C6S2 bridges: synthesis, crystal structure, and properties.

Two dragons playing ball: Direct metal-metal bond formation using a pi-conjugated dinuclear metalladithiolene complex with two electron-deficient metal centers as building blocks led to a cyclic double trinuclear heterometalladithiolene cluster with two parallel plane bridges (see structure; Rh pink, Mo green, S yellow, C gray, O red).

[Sarcolemmal sodium-calcium exchanger mediated the beneficial effects of myocardial ischemic preconditioning and pharmacological preconditioning].

OBJECTIVE: To investigate the role of sodium-calcium exchanger (NCX) on ischemic preconditioning and pharmacological preconditioning. METHODS: Cultured rat neonatal cardiomyocytes were randomly divided into 6 groups: (1) ischemia/reperfusion group (9 h ischemia followed by 1 h reperfusion, I/R), (2) ischemic preconditioning group (1.5 h ischemia/1 h reperfusion + I/R), (3) pharmacologic preconditioning group, adenosine (10 micromol/L) pretreated for 1 h + I/R, (4) calmodulin-dependent protein kinase II (CaMKII) inhibitor KN-93 (0.5 micromol/L for 0.5 h) + ischemic preconditioning group, (5) KN-93 + pharmacologic preconditioning group, (6) control group. The leakage of intracellular lactate dehydrogenase (LDH) in various groups was determined by biochemical autoanalyzer. Semi-quantitative RT-PCR was employed to measure the mRNA levels of sodium-calcium exchanger. Activity of sodium-calcium exchanger (Na(+)-dependent (45)Ca(2+) uptake) was measured by liquid scintillation counting. RESULTS: (1) Compared to the I/R group, the LDH leakages in both ischemic preconditioning group and pharmacologic preconditioning group were significantly reduced (P < 0.05) while significantly increased in the KN-93 + pharmacologic preconditioning group and the KN-93 + ischemic preconditioning group (P < 0.05). (2) The Na(+)-dependent (45)Ca(2+) uptake was significantly increased in the I/R group (P < 0.05) compared to control group and this increase could be significantly attenuated in ischemic preconditioning group and adenosine pretreatment group (P < 0.05). (3) The expression of NCX mRNA in I/R group was also significantly increased (P < 0.05) in the I/R group (P < 0.05) compared to control group and this increase could be significantly attenuated in ischemic preconditioning group and adenosine pretreatment group (P < 0.05), CaMKII inhibitor KN-93 significantly abolished these effects in preconditioning group (P < 0.05) and in adenosine pretreated group (P < 0.05). CONCLUSION: NCX mediated the cardioprotective effects of ischemic preconditioning and pharmacological preconditioning in the neonatal cardiomyocytes I/R model.