Two birds with one stone: One-pot concurrent Ta-doping and -coating on Ni-rich LiNi0.92Co0.04Mn0.04O2 cathode materials with fiber-type microstructure and Li+-conducting layer formation

A novel scalable Taylor-Couette reactor (TCR) synthesis method was employed to prepare Ta-modified LiNi0.92Co0.04Mn0.04O2 (T-NCM92) with different Ta contents. Through experiments and density functional theory (DFT) calculations, the phase and microstructure of Ta-modified NCM92 were analyzed, showing that Ta provides a bifunctional (doping and coating at one time) effect on LiNi0.92Co0.04Mn0.04O2 cathode material through a one-step synthesis process via a controlling suitable amount of Ta and Li-salt. Ta doping allows the tailoring of the microstructure, orientation, and morphology of the primary NCM92 particles, resulting in a needle-like shape with fine structures that considerably enhance Li+ ion diffusion and electrochemical charge/discharge stability. The Ta-based surface-coating layer effectively prevented microcrack formation and inhibited electrolyte decomposition and surface-side reactions during cycling, thereby significantly improving the electrochemical performance and long-term cycling stability of NCM92 cathodes. Our as-prepared NCM92 modified with 0.2 mol% Ta (i.e., T2-NCM92) exhibits outstanding cyclability, retaining 84.5 % capacity at 4.3 V, 78.3 % at 4.5 V, and 67.6 % at 45 ℃ after 200 cycles at 1C. Even under high-rate conditions (10C), T2-NCM92 demonstrated a remarkable capacity retention of 66.9 % after 100 cycles, with an initial discharge capacity of 157.6 mAh g-1. Thus, the Ta modification of Ni-rich NCM92 materials is a promising option for optimizing NCM cathode materials and enabling their use in real-world electric vehicle (EV) applications.

Concerted Effect of Ion- and Electron-Conductive Additives on the Electrochemical and Thermal Performances of the LiNi0.8Co0.1Mn0.1O2 Cathode Material Synthesized by a Taylor-Flow Reactor for Lithium-Ion Batteries

To address the issue that a single coating agent cannot simultaneously enhance Li+-ion transport and electronic conductivity of Ni-rich cathode materials with surface modification, in the present study, we first successfully synthesized a LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode material by a Taylor-flow reactor followed by surface coating with Li-BTJ and dispersion of vapor-grown carbon fibers treated with polydopamine (PDA-VGCF) filler in the composite slurry. The Li-BTJ hybrid oligomer coating can suppress side reactions and enhance ionic conductivity, and the PDA-VGCFs filler can increase electronic conductivity. As a result of the synergistic effect of the dual conducting agents, the cells based on the modified NCM811 electrodes deliver superior cycling stability and rate capability, as compared to the bare NCM811 electrode. The CR2032 coin-type cells with the NCM811@Li-BTJ + PDA-VGCF electrode retain a discharge specific capacity of ∼92.2% at 1C after 200 cycles between 2.8 and 4.3 V (vs Li/Li+), while bare NCM811 retains only 84.0%. Moreover, the NCM811@Li-BTJ + PDA-VGCF electrode-based cells reduced the total heat (Qt) by ca. 7.0% at 35 °C over the bare electrode. Remarkably, the Li-BTJ hybrid oligomer coating on the surface of the NCM811 active particles acts as an artificial cathode electrolyte interphase (ACEI) layer, mitigating irreversible surface phase transformation of the layered NCM811 cathode and facilitating Li+ ion transport. Meanwhile, the fiber-shaped PDA-VGCF filler significantly reduced microcrack propagation during cycling and promoted the electronic conductance of the NCM811-based electrode. Generally, enlightened with the current experimental findings, the concerted ion and electron conductive agents significantly enhanced the Ni-rich cathode-based cell performance, which is a promising strategy to apply to other Ni-rich cathode materials for lithium-ion batteries.

[Phase Ⅱ clinical trial of PD-1 inhibitor combined with chemotherapy for locally advanced resectable oral squamous cell carcinoma]

Objective: To explore the effectiveness and safety of programmed death 1(PD-1) inhibitory combined with chemotherapy as a neoadjuvant therapy for locally advanced resectable oral squamous cell carcinoma. Methods: This study was a randomized controlled phase Ⅱ trial. Patients recruited from Tianjin Medical University Cancer Institute and Hospital from July 2021 to February 2023 were randomly divided into two groups in a 1∶1 ratio: the experimental group (Toripalimab combined with albumin paclitaxel and cisplatin) and the control group (albumin paclitaxel and cisplatin); patients in both groups underwent three cycles of neoadjuvant therapy. After completion of neoadjuvant therapy, patients were evaluated and subsequent surgical treatment was performed. According to the completion of treatment, the analysis was conducted on both the full analysis set and the protocol set. The effectiveness and safety of treatments were evaluated. SPSS 20.0 software was used for statistical analysis. Results: A total of 41 cases with oral cancer were enrolled, including 26 males and 15 females, aged between 34 and 74 years old. There were 23 cases in the experimental group and 18 cases in the control group. A total of 23 cases completed neoadjuvant therapy and surgery according to the protocol. Experimental group and control group showed respectively the complete response rates of 1/19 and 0/17, the partial response rates of 13/19 and 8/17, the stage-down rates of 4/19 and 3/17, the pathologic complete response rate of 8/14 and 2/9, with no statistically significant differences in individual rates between two groups (P>0.05). The major pathological response rate of 13/14 in experimental group was higher than that of 2/9 in control group (P<0.05). The incidence of grade 3-4 adverse reactions related to treatment was low in both groups (4/23 vs. 3/18, χ2=0.13, P=0.72), and the most common serious adverse reactions in the experimental group were granulocyte deficiency and electrolyte disorder. There were no adverse reactions that affected subsequent surgical treatment or caused death, and the safety and tolerability were good. The median follow-up time was 15 months, and the one-year disease-free survival rate of the experimental group was higher than that of control group (92.86% vs. 77.78%, χ2=0.62, P=0.42), with a relative decrease of 87% in the risk of disease progression or death (P=0.029). For patients with programmed death-ligand 1(PD-L1) protein expression combined positive score≥20, the experimental group showed higher major pathological response rate than control group (5/5 vs. 0/4, P=0.03). Conclusion: The neoadjuvant therapy of immunotherapy combined with chemotherapy can improve the pathological remission of oral squamous cell carcinoma and the long-term survival benefits and the prognosis of patients.

Measurements of All-Particle Energy Spectrum and Mean Logarithmic Mass of Cosmic Rays from 0.3 to 30 PeV with LHAASO-KM2A

We present the measurements of all-particle energy spectrum and mean logarithmic mass of cosmic rays in the energy range of 0.3-30 PeV using data collected from LHAASO-KM2A between September 2021 and December 2022, which is based on a nearly composition-independent energy reconstruction method, achieving unprecedented accuracy. Our analysis reveals the position of the knee at 3.67±0.05±0.15  PeV. Below the knee, the spectral index is found to be -2.7413±0.0004±0.0050, while above the knee, it is -3.128±0.005±0.027, with the sharpness of the transition measured with a statistical error of 2%. The mean logarithmic mass of cosmic rays is almost heavier than helium in the whole measured energy range. It decreases from 1.7 at 0.3 PeV to 1.3 at 3 PeV, representing a 24% decline following a power law with an index of -0.1200±0.0003±0.0341. This is equivalent to an increase in abundance of light components. Above the knee, the mean logarithmic mass exhibits a power law trend towards heavier components, which is reversal to the behavior observed in the all-particle energy spectrum. Additionally, the knee position and the change in power-law index are approximately the same. These findings suggest that the knee observed in the all-particle spectrum corresponds to the knee of the light component, rather than the medium-heavy components.

Unveiling high-power and high-safety lithium-ion battery separator based on interlayer of ZIF-67/cellulose nanofiber with electrospun poly(vinyl alcohol)/melamine nonwoven membranes

Due to the poor thermal stability of conventional separators, lithium-ion batteries require a suitable separator to maintain system safety for long-term cycling performance. It must have high porosity, superior electrolyte uptake ability, and good ion-conducting properties even at high temperatures. In this work, we demonstrate a novel composite membrane based on sandwiching of zeolitic imidazole frameworks-67 decorated cellulose acetate nanofibers (ZIF-67@CA) with electrospun poly(vinyl alcohol)/melamine (denoted as PVAM) nonwoven membranes. The as-prepared sandwich-type membranes are called PVAM/x%ZIF-67@CA/PVAM. The middle layer of composite membranes is primarily filled with different weight percentages of ZIF-67 nanoparticles (x = 5, 15, and 25 wt%), which both reduces the non-uniform porous structure of CA and increases its thermal stability. Therefore, our sandwich-type PVAM/x%ZIF-67@CA/PVAM membrane exhibits a higher thermal shrinkage effect at 200 °C than the commercial polyethylene (PE) separator. Due to its high electrolyte uptake (646.8%) and porosity (85.2%), PVAM/15%ZIF-67@CA/PVAM membrane achieved high ionic conductivity of 1.46 × 10-3 S cm-1 at 70 °C, as compared to the commercial PE separator (ca. 6.01 × 10-4 S cm-1 at 70 °C). Besides, the cell with PVAM/15%ZIF-67@CA/PVAM membrane shows an excellent discharge capacity of about 167.5 mAh g-1after 100 cycles at a 1C rate with a capacity retention of 90.3%. The ZIF-67 fillers in our sandwich-type composite membrane strongly attract anions (PF6-) through Lewis' acid-base interaction, allowing uniform Li+ ion transport and suppressing Li dendrites. As a result, we found that the PVAM/15%ZIF-67@CA/PVAM composite nonwoven membrane is applicable to high-power, high-safety lithium-ion battery systems that can be used in electric vehicles (EVs).

Measurement of Ultra-High-Energy Diffuse Gamma-Ray Emission of the Galactic Plane from 10 TeV to 1 PeV with LHAASO-KM2A

The diffuse Galactic γ-ray emission, mainly produced via interactions between cosmic rays and the interstellar medium and/or radiation field, is a very important probe of the distribution, propagation, and interaction of cosmic rays in the Milky Way. In this Letter, we report the measurements of diffuse γ rays from the Galactic plane between 10 TeV and 1 PeV energies, with the square kilometer array of the Large High Altitude Air Shower Observatory (LHAASO). Diffuse emissions from the inner (15°10  TeV). The energy spectrum in the inner Galaxy regions can be described by a power-law function with an index of -2.99±0.04, which is different from the curved spectrum as expected from hadronic interactions between locally measured cosmic rays and the line-of-sight integrated gas content. Furthermore, the measured flux is higher by a factor of ∼3 than the prediction. A similar spectrum with an index of -2.99±0.07 is found in the outer Galaxy region, and the absolute flux for 10≲E≲60  TeV is again higher than the prediction for hadronic cosmic ray interactions. The latitude distributions of the diffuse emission are consistent with the gas distribution, while the longitude distributions show clear deviation from the gas distribution. The LHAASO measurements imply that either additional emission sources exist or cosmic ray intensities have spatial variations.

Socio-economic disparities in exposure to and endorsement of COVID-19 vaccine misinformation and the associations with vaccine hesitancy and vaccination

OBJECTIVES

We examined disparities in vaccine misinformation exposure and endorsement and the associations with vaccine hesitancy and vaccination uptake.

STUDY DESIGN

Population-based survey.

METHODS

A population-based survey was conducted on 5,002 Hong Kong adults oversampling low socio-economic status (SES, n = 2,200). Information on exposure (13 misinformation statements, total 0-13, median = 2), endorsement (13 statements, score 0-10, high scores indicate higher levels of endorsement, median = 5.75) of misinformation, vaccine hesitancy (14 items, score 1-5), and vaccination (two doses) were collected. Multivariable regression (adjusted β [aβ]) and Poisson regression (adjusted risk ratio [aRR]) adjusting for demographic characteristics were used to examine the associations of exposure to and endorsement of misinformation with vaccine hesitancy and vaccination.

RESULTS

A total of 71.8% of respondents had at least exposure to one vaccine misinformation, and 35.7% had a high level of endorsement (median or above). Respondents with lower SES had a lower exposure (≤2 statements, 57.1% vs 50.1%, P < 0.001) but a higher level of endorsement (36.6% vs 34.9%, P = 0.01) of misinformation. Overall, 72.9% had been vaccinated for two or more doses, with a lower proportion in respondents with lower SES (83.6% vs 61.1%; P < 0.001). Compared with no exposure to misinformation, high levels of exposure and endorsement were associated with vaccine hesitancy (aβ = 0.44, 95% confidence interval 0.40-0.48; aβ = 0.50, 0.47-0.54, respectively) and lower vaccination rates (aRR = 0.98, 0.97-0.99; aRR = 0.92, 0.88-0.96, respectively). Vaccine hesitancy mediated the associations of exposure (fully, 100%) and endorsement (partially, 73%) with vaccination uptake.

CONCLUSION

Endorsement of vaccine misinformation in respondents with lower SES was associated with low vaccination uptake.

A tera-electron volt afterglow from a narrow jet in an extremely bright gamma-ray burst

Some gamma-ray bursts (GRBs) have a tera-electron volt (TeV) afterglow, but the early onset of this has not been observed. We report observations with the Large High Altitude Air Shower Observatory of the bright GRB 221009A, which serendipitously occurred within the instrument field of view. More than 64,000 photons >0.2 TeV were detected within the first 3000 seconds. The TeV flux began several minutes after the GRB trigger, then rose to a peak about 10 seconds later. This was followed by a decay phase, which became more rapid ~650 seconds after the peak. We interpret the emission using a model of a relativistic jet with half-opening angle ~0.8°. This is consistent with the core of a structured jet and could explain the high isotropic energy of this GRB.

Preparation of long-term cycling stable ni-rich concentration-gradient NCMA cathode materials for li-ion batteries

Nickel-rich (Ni > 90 %) cathodes are regarded as one of the most attractive because of their high energy density, despite their poor stability and cycle life. To improve their performance, in this study we synthesized a double concentration-gradient layered Li[Ni_0.90Co_0.04Mn_0.03Al_0.03]O₂ oxide (CG-NCMA) using a continuous co-precipitation Taylor-Couette cylindrical reactor (TCCR) with a Ni-rich-core, an Mn-rich surface, and Al on top. The concentration-gradient morphology was confirmed through cross-sectional EDX line scanning. The as-synthesized sample exhibited excellent electrochemical performance at high rates (5C/10C), as well as cyclability (91.5 % after 100 cycles and 70.3 % after 500 cycles at 1C), superior to that (83.4 % and 47.6 %) of its non-concentration-gradient counterpart (UC-NCMA). The Mn-rich surface and presence of Al helped the material stay structurally robust, even after 500 cycles, while also suppressing side reactions between the electrode and electrolyte, resulting in better overall electrochemical performance. These enhancements in performance were studied using TEM, SEM, in-situ-XRD, XPS, CV, EIS and post-mortem analyses. This synthetic method enables the highly scalable production of CG-NCMA samples with two concentration-gradient structures for practical applications in Li-ion batteries.

Constraints on Heavy Decaying Dark Matter from 570 Days of LHAASO Observations

The kilometer square array (KM2A) of the large high altitude air shower observatory (LHAASO) aims at surveying the northern γ-ray sky at energies above 10 TeV with unprecedented sensitivity. γ-ray observations have long been one of the most powerful tools for dark matter searches, as, e.g., high-energy γ rays could be produced by the decays of heavy dark matter particles. In this Letter, we present the first dark matter analysis with LHAASO-KM2A, using the first 340 days of data from 1/2-KM2A and 230 days of data from 3/4-KM2A. Several regions of interest are used to search for a signal and account for the residual cosmic-ray background after γ/hadron separation. We find no excess of dark matter signals, and thus place some of the strongest γ-ray constraints on the lifetime of heavy dark matter particles with mass between 10^{5} and 10^{9}  GeV. Our results with LHAASO are robust, and have important implications for dark matter interpretations of the diffuse astrophysical high-energy neutrino emission.

Lithium Nafion-Modified Li6.05Ga0.25La3Zr2O11.8F0.2 Trilayer Hybrid Solid Electrolyte for High-Voltage Cathodes in All-Solid-State Lithium-Metal Batteries

All-solid-state batteries containing ceramic-polymer solid electrolytes are possible alternatives to lithium-metal batteries containing liquid electrolytes in terms of their safety, energy storage, and stability at elevated temperatures. In this study we prepared a garnet-type Li_6.05Ga_0.25La₃Zr₂O_11.8F_0.2 (LGLZOF) solid electrolyte modified with lithium Nafion (LiNf) and incorporated it into poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) matrixes. We used a solution-casting method to obtain bilayer (Bi-HSE) and trilayer (Tri-HSE) hybrid solid electrolytes. A layer of functionalized multiwalled carbon nanotubes (f-MWCNTs) coated with LiNf (LiNf@f-MWCNT) in the Tri-HSE led to good compatibility with the polymer slurry and adhered well to the Li anode, thereby improving the interfacial contact at the electrode-solid electrolyte interface and suppressing dendrite growth. The Tri-HSE membrane displayed high ionic conductivity (5.6 × 10^-4 S cm^-1 at 30 °C), a superior Li⁺ transference number (0.87), and a wide electrochemical window (0-5.0 V vs Li/Li⁺). In addition, Li symmetrical cells incorporating this hybrid electrolyte possessed excellent interfacial stability over 600 h at 0.1 mA cm^-2 and a high critical current density (1.5 mA cm^-2). Solid-state lithium batteries having the structure LiNf@LiNi_0.8Co_0.1Mn_0.1O₂/Tri-HSE/Li delivered excellent room-temperature stable cycling performance at 0.5C, with a capacity retention of 85.1% after 450 cycles.

In Situ Co-O Bond Reinforcement of the Artificial Cathode Electrolyte Interphase in Highly Delithiated LiCoO2 for High-Energy-Density Applications

Highly delithiated LiCoO₂ has high specific capacity (>200 mAh g^-1); however, its degradation behavior causes it to have poor electrochemical performance and thermal instability. The degradation of highly delithiated LiCoO₂ is mainly induced by oxygen vacancy migration and weakening of oxygen-related interactions, which result in pitting corrosion and fault formation on the surface. In this research, a coupling agent, namely, 3-aminopropyltriethoxysilane (APTES), was grafted onto the surface of LiCoO₂ to form a cross-linking structure. Through the aza-Michael addition reaction, an oligomer formed from barbituric acid and bisphenol a diglycidyl ether diacrylate were reacted with the cross-linking APTES to form an artificial cathode electrolyte interphase (ACEI). The highly delithiated LiCoO₂ containing the ACEI had considerably less degradation on the surface of the bulk material caused by oxygen release. The formation of the O1 phase was prevented in high delithiation and high-temperature operations. This research revealed that the ACEI reinforced the Co-O bond, which is crucial in preventing gas evolution and O1 phase formation. In addition, the ACEI prevents direct contact between the electrolyte and highly active surface of LiCoO₂, thereby preventing the formation of a thick and high impedance traditional cathode electrolyte interphase. According to the present results, highly delithiated LiCoO₂ containing the ACEI exhibited outstanding cycle retention and capacity at 55 °C as well as low heat capacity release in the fully delithiated state. The ACEI considerably protected and maintained the electrochemical performance of highly delithiated LiCoO₂, which is suitable for high-energy-density applications, such as electric vehicles and power tools.

[Application of weighted adjustments of dropout rates in sensitivity analysis of medical repeated measurements data and implementation with SAS]

Objective: To explore the application of weighted adjustments of dropout rates in sensitivity analysis of medically repeated measurements data and the implementation with SAS 9.4 software. Methods: By compiling SAS codes, mixed-effects models for repeated measures were used to conduct the covariance analysis of multivariable repeated measurements data. Meanwhile, the overall dropout rate and the dropout rates of each group were used to make weighted adjustments by applying pattern-mixture models, which was considered to be a sensitivity analysis to validate the stability of results. Results: The dropout rates of placebo group, low-dose and high-dose groups were 8.77%, 11.79% and 16.15%, respectively, the differences were significant (P=0.025). The results of mixed-effects models for repeated measures showed the differences of curative effect indicators changes from baselines of between high-dose, low-dose groups and placebo group were significant (P=0.008 and P=0.002). The results of pattern-mixture models considering weighted adjustments of the respective groups' dropout rates were consistent with those of mixed-effects models for repeated measures. Conclusions: The pattern-mixture models considering weighted adjustments of dropout rates can be used in the sensitivity analysis of repeated measurements data. The SAS codes can provide a practical basis for the popularization and application of weighted adjustments of dropout rates in the sensitivity analysis of repeated measurements data.

[Effects of Janus kinase/signal transduction and activator of transcription 3 pathway inhibitor in skeletal muscle function in severely burned rats and its mechanism]

Objective: To observe the functional changes of skeletal muscle in severely burned rats, and to investigate the effects and possible mechanisms of Janus kinase/signal transducer and activator of transcription 3 (JAK/STAT3) pathway inhibitor in skeletal muscle function. Methods: The experiment research method was applied. One hundred and twenty male Wistar rats of 8-week-old were divided into sham injury group, simple burn group, and burn+JAK/STAT3 inhibitor group according to the random number table, with 40 rats in each group. Rats in simple burn group and burn+JAK/STAT3 inhibitor group were inflicted with 50% total body surface area full-thickness scald on the back and abdomen, and rats in sham injury group were sham injured. Rats in burn+JAK/STAT3 inhibitor group were intraperitoneally injected with JAK/STAT3 inhibitor ruxolitinib. On post injury day (PID) 0 (immediately), 1, 4, 7, and 14, 8 rats in each group were used to measure the specific force generated by extensor digitorum longus in optimal length stimulated with pulse frequency of 20, 40, 60, 80, 100, 120, 140, and 160 Hz using a multichannel electrophysiological instrument, and specific force in fatigue period of extensor digitorum longus in optimal length stimulated with pulse frequency of 50 Hz for 0, 10, 20, 30, 60, 120, 180, 240, and 300 s. On PID 0, 1, 4, 7, and 14, carbonyl compound content of extensor digitorum longus was determined by ultraviolet spectrophotometry, and ATP content of extensor digitorum longus was determined by micrometry. Data were statistically analyzed with analysis of variance for repeated measurement, analysis of variance for factorial design, Bonferroni method, and t test. Results: Compared with those of sham injury group, specific forces of extensor digitorum longus of rats in simple burn group were significantly decreased after being stimulated with all the pulse frequency on PID 0, 1, 7, and all the pulse frequency except for 20 Hz on PID 4, and pulse frequency of 20 and 40 Hz on PID 14 (P<0.05 or P<0.01). Compared with those of simple burn group, specific forces of extensor digitorum longus of rats in burn+JAK/STAT3 inhibitor group were significantly increased after being stimulated with all the pulse frequency except for 20 Hz on PID 1 and all the pulse frequency on PID 4, 7, and 14 (P<0.05 or P<0.01). Compared with those of sham injury group, specific forces of extensor digitorum longus of rats in simple burn group were significantly decreased in fatigue period at all the time points post injury and stimulation time points except for 240 s on PID 7 (P<0.05 or P<0.01). Compared with those of simple burn group, specific forces of extensor digitorum longus of rats in burn+JAK/STAT3 inhibitor group were obviously increased in fatigue period at all the stimulation time points except for 60 and 300 s on PID 1 and 240 s on PID 4, and all the stimulation time points on PID 7 and 14 (P<0.05 or P<0.01). The carbonyl compound content of extensor digitorum longus of rats in simple burn group on PID 0, 1, 4, 7, and 14 was (0.651±0.155), (0.739±0.194), (0.618±0.086), (0.813±0.162), (0.615±0.115) nmol/mg, which were obviously higher than (0.196±0.019), (0.156±0.004), (0.169±0.023) (0.156±0.027), (0.175±0.008) nmol/mg in sham injury group (t=7.219, 6.491, 10.938, 9.182, 11.589, P<0.01) and (0.538±0.069), (0.369±0.059), (0.273±0.061), (0.334±0.109), (0.318±0.101) nmol/mg in burn+JAK/STAT3 inhibitor group (t=2.446, 4.689, 8.355, 5.754, 6.097, P<0.05 or P<0.01). The ATP content in extensor digitorum longus of rats in simple burn group on PID 1, 4, 7, and 14 was obviously lower than that in sham injury group (t=7.159, 7.591, 7.473, 4.026, P<0.01) and burn+JAK/STAT3 inhibitor group (t=2.295, 2.575, 2.453, 2.997, P<0.05). Conclusions: After severe burn, the specific force of extensor digitorum longus in rats decreased significantly after being stimulated with different pulse frequencies, and the extensor digitorum longus in rats was prone to fatigue. Blocking the JAK/STAT3 signaling pathway can reduce the oxidative stress of muscle protein and increase ATP content, thereby reducing the muscle strength decline caused by burn injury and improving the muscle strength decline during fatigue period.

[Research on ZNA probe in the quantitative detection of chlamydia trachomatis nucleic acid]

Objective: To investigate the performance of ZNA(ZIP Nucleic Acid) probes and its application in the quantitative detection of Chlamydia trachomatis (CT)nucleic acid. Methods: Use CT positive plasmids to compare the PCR amplification curves of ZNA probes coupled with different ZIP numbers. Compare ZNA probes with other three sets of probes [namely, 29mer ordinary Taqman probes (long-DNA probe), 20mer ordinary Taqman probes (short-DNA probe) and MGB probes] for stability in PCR amplification curves and repeated freezing and thawing, and the difference in the detection rate of low-concentration plasmids. Use CT positive clinical samples to compare the difference in amplification curves between ZNA probes, long-DNA probe, short-DNA probe and MGB probes, and the detection rate of low-concentration samples. Results: (1) The Ct value and fluorescence value of the probes coupled with 5ZIP units are both better than those coupled with a smaller number of ZIPs. And the difference is biggest when compared with only coupled with 1 ZIP unit: Ct value increased by 1.34 (sensitivity increased by 2.37 times), and fluorescence value increased by 30%. (2) The amplification efficiency of the ZNA probe coupled with 5 ZIPs is 2.14-2.64 times that of the preferred ordinary Taqman probe and MGB probe, and the fluorescence value is 17%-90% higher. (3) The probe freeze-thaw stability results show that the ZNA probe has the best stability, and the lowest concentration of Ct value has the smallest deviation (CV% = 1.4), which is better than the other three sets of probes (CV%=1.7-3.7). (4) Using 35 CT positive clinical samples to compare the PCR amplification performance, compared with other three sets of probes, the amplification sensitivity of ZNA probes was increased by 1.60, 0.99 and 1.06 times respectively. And the results of the consistency analysis of the Ct value show that compared with short-DNA probe and MGB probes, ZNA probes have better detection performance for clinical samples. (5) Use low concentration plasmid template (200, 100, 50 and 10 copies/mL respectively) to compare the amplification sensitivity of the four sets of probes, the detection rate of ZNA probe is the best. Especially, at the lowest concentration 10 copies/mL, the detection rate of the other sets of probes is only 15%-20%, but the ZNA probe is still 30%. (6) In 20 clinical samples with different low concentrations (200, 150, 100, and 50 copies/mL), the detection rate of ZNA probes was the highest, which were 100%, 95%, 90%, and 70%, respectively. Conclusions: Through testing of the amplification efficiency, fluorescence value, freeze-thaw stability, the amplification performance of clinical samples and the detection sensitivity of low-concentration samples, ZNA probes coupled with 5 ZIPs show better performance than ordinary Taqman probes and MGB probes. As a new probe technology with flexible design and easy synthesis, ZNA probe can further improve detection sensitivity of low concentration samples in the field of gene expression.

[Repair of skin and soft tissue defects in shoulder and elbow with rotator scapular artery perforator flap, lateral thoracic perforator flap, or medial brachial artery perforator flap]

From January 2014 to June 2018, 12 patients with skin and soft tissue defects in shoulder and elbow were admitted to General Hospital of Ningxia Medical University with skin and soft tissue defect size of 6 cm×5 cm to 11 cm×8 cm, including 9 males and 3 females aged 15-56 years. Wounds of 5 patients were repaired with rotator scapular artery perforator flap (flap area of 8 cm×7 cm to 12 cm×6 cm), and the donor flap area was sutured directly. Wounds of 3 patients were repaired with lateral thoracic perforator flap (flap area of 8 cm×7 cm to 13 cm×9 cm). The donor flap area of two patients was sutured directly, the majority of the donor flap area of one patient was sutured directly, and a small part was covered by split-thickness skin graft from ipsilateral thigh. Wounds of 4 patients were repaired with medial brachial artery perforator flap (flap area of 6 cm×5 cm to 12 cm×10 cm). The donor flap area of two patients was sutured directly, and two patients were covered with split-thickness skin graft from left chest wall. The flaps of 11 patients survived after surgery. Blood flow disorder at the distal end of the flap was observed in one patient. After treatment, the distal end of the flap presented 3 cm×2 cm necrosis, and the skin graft survived after second skin grafting and debridement. During the follow-up of 6 to 24 months post surgery, all patients had good texture of flap, with light scar hyperplasia in the donor flap area, and good recovery of elbow and shoulder joint function. The rotator scapular artery perforator flap, lateral thoracic perforator flap, and medial brachial artery perforator flap with the advantages being of relatively simple operation, high survival rate, and good surgical outcome, are good choices for repairing the skin and soft tissue defects in shoulder and elbow.

Polymorphisms in the androgen receptor CAG repeat sequence are related to tumour stage but not to ERG or androgen receptor expression in Malaysian men with prostate cancer

INTRODUCTION

Polymorphic expression of a CAG repeat sequence in the androgen receptor (AR) gene may influence the activity of the AR and the occurrence of prostate cancer and the TMPRSS2-ERG fusion event. Furthermore, this polymorphism may be responsible for the ethnic variation observed in prostate cancer occurrence and expression of the ERG oncogene. We investigate the expression of AR and ERG in the biopsies of Malaysian men with prostate cancer and in the same patients relate this to the length of the CAG repeat sequence in their AR gene.

MATERIALS AND METHODS

From a PSA screening initiative, 161 men were shown to have elevated PSA levels in their blood and underwent prostatic tissue biopsy. DNA was extracted from the blood, and exon 1 of the AR gene amplified by PCR and sequenced. The number of CAG repeat sequences were counted and compared to the immunohistochemical expression of ERG and AR in the matched tumour biopsies.

RESULTS

Of men with elevated PSA, 89 were diagnosed with prostate cancer, and 72 with benign prostatic hyperplasia (BPH). There was no significant difference in the length of the CAG repeat in men with prostate cancer and BPH. The CAG repeat length was not associated with; age, PSA or tumour grade, though a longer CAG repeat was associated with tumour stage. ERG and AR were expressed in 36% and 86% of the cancers, respectively. There was no significant association between CAG repeat length and ERG or AR expression. However, there was a significant inverse relationship between ERG and AR expression. In addition, a significantly great proportion of Indian men had ERG positive tumours, compared to men of Malay or Chinese descent.

CONCLUSIONS

CAG repeat length is not associated with prostate cancer or expression of ERG or AR. However, ERG appears to be more common in the prostate cancers of Malaysian Indian men than in the prostate cancers of other Malaysian ethnicities and its expression in this study was inversely related to AR expression.

[Current status of national free antiretroviral therapy in interprovincial migrating people living with HIV/AIDS and influencing factors, China, 2011-2015]

Objective: To understand the current status of national free antiretroviral therapy in interprovincial migrating people living with HIV/AIDS (PLWHA) and influencing factors in China. Methods: Descriptive and trend test analyses were performed to evaluate the historical characteristics and trends of main descriptive indicators on national free antiretroviral therapy for the interprovincial migrating PLWHA by using the data collected from National Comprehensive HIV/AIDS Information System from 2011 to 2015. Logistic regression model was used to explore the main factors that influencing the coverage of national free antiretroviral therapy among the interprovincial migrating PLWHA in China. Results: The proportion of interprovincial migrating PLWHA gradually increased in last 5 years from 7.1% (17 784/250 645) in 2011 to 10.3% (54 596/528 226) in 2015 (Z=51.38, P<0.000 1) in China. The coverage rate of free antiretroviral therapy in interprovincial migrating PLWHA increased from 37.3% (6 641/17 784) in 2011 to 71.0% (38 783/54 596) in 2015, showing a significant rising tendency (Z=96.23, P<0.000 1), but it was slightly lower than that in non-interprovincial migrating PLWHA in 2015 (71.5%, 338 654/473 630). Multivariate logistic regression analysis showed that the PLWHA who were females, aged ≥50 years, of Han ethnic group, married or had spouse, had the educational level of high school or above, infected through homosexual intercourse, with CD(4)(+)T cells counts ≤500 cells/μl at the first visit, identified to be infected with HIV in medical setting, living in urban areas et al, were more likely to receive free antiretroviral therapy. Conclusions: The coverage rate of free antiretroviral therapy varied among the interprovincial migrating PLWHA with different characteristics. It is still necessary to take effective measures to further increase the coverage of free antiretroviral therapy in interprovincial migrating PLWHA and to include the free antiretroviral therapy in interprovincial migrating PLWHA into standardized management system as soon as possible.

[Study on the application of dexmedetomidine combined with remifentanil in dressing change of conscious patients with non-intubation in burn intensive care unit]

Objective: To observe the analgesic and sedative effect and safety of application of dexmedetomidine combined with remifentanil in dressing change of conscious patients with non-intubation in burn intensive care unit. Methods: Forty patients conforming to the study criteria hospitalized in our burn intensive care unit from April 2015 to April 2017 were selected. Prospective, randomized, and double-blind method was used for the design. Patients were divided into dexmedetomidine group and dexmedetomidine+ remifentanil group according to the random number table, with 20 cases in each group. Patients in the two groups were respectively given corresponding drugs during dressing change. The frequency and time of dressing change, Verbal Rating Scale (VRS) score of patients during dressing change (at drug administration for 25 minutes) and after dressing change (25 min after dressing change), Ramsay Sedation Score (RSS) during dressing change, satisfaction level for anesthesia of the patients and physicians after dressing change, dosage of remifentanil, and various adverse effects during and after dressing change were recorded. The heart rate, mean arterial blood pressure (MAP), respiratory rate, and pulse oxygen saturation (SpO₂) before drug administration and at 10, 15, and 25 minutes after drug administration were also recorded. Data were processed with analysis of variance for repeated measurement, t test, chi-square test, and Fisher's exact probability test. Results: (1) Totally 38 patients completed the trial. There were no statistically significant differences between patients in two groups in gender, American Association of Anesthesiologist Grading, age, weight, and total burn area (χ²=0.230, 0.146, t=0.224, 0.351, 0.367, P>0.05). (2) The frequency of dressing change of patients in two groups were both 48 times. The time of dressing change and VRS scores during dressing change of patients in two groups were similar (t=0.821, 1.522, P>0.05). The VRS score of patients in dexmedetomidine+ remifentanil group after dressing change was (3.1±0.4) points, obviously lower than (3.8±0.8) points in remifentanil group (t=2.213, P<0.05). The RSS, satisfaction level scores for anesthesia of the patients and physicians after dressing change in dexmedetomidine+ remifentanil group were (3.13±0.32), (3.44±0.41), and (3.13±0.25) points, respectively, obviously better than (1.82±0.24), (2.71±0.23), (2.53±0.41) points in remifentanil group (t=2.226, 2.684, 7.702, P<0.01). The dosage of remifentanil of patients in dexmedetomidine+ remifentanil group was (282±19) μg, obviously less than (340±31) μg in remifentanil group (t=9.896, P<0.01). There were no statistically significant differences between patients in two groups in rates of respiratory inhibition and hypotension (χ²=0.211, 0.154, P>0.05). Compared with those in remifentanil group, the rates of nausea, vomiting, and other gastrointestinal symptoms of patients in dexmedetomidine+ remifentanil group were obviously reduced (P<0.05), but the rate of bradycardia was obviously increased (χ²=6.008, P<0.05). (3) There were no statistically significant differences between patients in two groups in heart rate, MAP, respiratory frequency, and SpO₂ before drug administration (t=0.444, 0.892, 1.059, 1.039, P>0.05). The heart rates of patients in dexmedetomidine+ remifentanil group at 10, 15, and 25 minutes after drug administration were (83±11), (78±10), and (82±14) times per minute, respectively, significantly lower than (95±10), (87±12), and (89±12) times per minute in remifentanil group (t=5.592, 3.992, 2.630, P<0.05 or P<0.01). The MAP of patients in dexmedetomidine+ remifentanil group at 15 and 25 minutes after drug administration were (69.4±3.1) and (73.8±2.2) mmHg (1 mmHg=0.133 kPa), respectively, significantly lower than (75.4±3.0) and (78.1±3.5) mmHg in remifentanil group (t=9.181, 7.206, P<0.01). There were no statistically significant differences between patients in two groups in respiratory frequency at each time point after drug administration (t=1.489, 1.862, 1.963, P>0.05). The SpO₂ of patients in dexmedetomidine+ remifentanil group at 15 minutes after drug administration was 0.972±0.018, obviously lower than 0.979±0.015 in remifentanil group (t=2.070, P<0.05). Conclusions: Application of remifentanil with small dosage has effective analgesia for conscious burn patients with non-intubation during dressing changes, however, adverse effects such as nausea and vomiting are likely to occur. Remifentanil combined with dexmedetomidine not only guarantee the analgesic effect, but also reduce the dosage of analgesics, improve the sedative effect and satisfaction of the patients for anesthesia, and reduce various adverse effects. However, it will increase the incidence of bradycardia and has some inhibition effect on circulation at the same time.

[Effects of arnebia root oil on wound healing of rats with full-thickness skin defect and the related mechanism]

Objective: To observe the effects of arnebia root oil on wound healing of rats with full-thickness skin defect, and to explore the related mechanism. Methods: Eighty SD rats were divided into arnebia root oil group and control group according to the random number table, with 40 rats in each group, then full-thickness skin wounds with area of 3 cm×3 cm were inflicted on the back of each rat. Wounds of rats in arnebia root oil group and control group were treated with sterile medical gauze and bandage package infiltrated with arnebia root oil gauze or Vaseline gauze, respectively, with dressing change of once every two days. On post injury day (PID) 3, 7, 14, and 21, 10 rats in each group were sacrificed respectively for general observation and calculation of wound healing rate. The tissue samples of unhealed wound were collected for observation of histomorphological change with HE staining, observation of expressions of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) with immunohistochemical staining, and determination of mRNA expressions of VEGF and bFGF with real time fluorescent quantitive reverse transcription polymerase chain reaction. Data were processed with analysis of variance of factorial design, t test, and Bonferroni correction. Results: (1) On PID 3, there were a few secretions in wounds of rats in the two groups. On PID 7, there were fewer secretions and more granulation tissue in wounds of rats in arnebia root oil group, while there were more secretions and less granulation tissue in wounds of rats in control group. On PID 14, most of the wounds of rats in arnebia root oil group were healed and there was much red granulation tissue in unhealed wounds, while part of wounds of rats in control group was healed and there were a few secretions and less granulation tissue in unhealed wounds. On PID 21, wounds of rats in arnebia root oil group were basically healed, while there were still some unhealed wounds of rats in control group. (2) On PID 3 and 7, the wound healing rates of rats in arnebia root oil group were (39±5)% and (46±4)% respectively, which were close to (34±3)% and (44±4)% of rats in control group (with t values respectively 0.807 and 0.481, P values above 0.05). On PID 14 and 21, the wound healing rates of rats in arnebia root oil group were (76±4)% and (90±3)% respectively, which were significantly higher than (60±6)% and (73±5)% of rats in control group (with t values respectively 2.308 and 3.072, P<0.05 or P<0.01). (3) On PID 3, 7, and 14, granulation tissue, fibroblasts, and nascent capillaries in unhealed wound tissue of rats in the two groups both gradually increased, and more ranulation tissue, fibroblasts, and nascent capillaries were seen in unhealed wound tissue of rats in arnebia root oil group. On PID 21, granulation tissue, fibroblasts, and nascent capillaries in unhealed wound tissue of rats in the two groups both gradually decreased. (4) On PID 3, 7, and 14, the numbers of VEGF positive cells and bFGF positive cells in unhealed wound tissue of rats in the two groups both gradually increased; there were more VEGF positive cells and bFGF positive cells in unhealed wound tissue of rats in arnebia root oil group than those in control group. On PID 21, positive expressions of VEGF and bFGF both decreased in unhealed wound tissue of rats in the two groups. (5) On PID 3, 7, and 14, mRNA expressions of VEGF in unhealed wound tissue of rats in arnebia root oil group were higher than those of control group (with t values from 2.967 to 4.173, P values below 0.01). On PID 21, mRNA expression of VEGF in unhealed wound tissue of rats in arnebia root oil group was lower than that of control group (t=-4.786, P<0.001). From PID 3 to 21, mRNA expressions of bFGF in unhealed wound tissue of rats in arnebia root oil group were higher than those of control group (with t values from 2.326 to 4.702, P<0.05 or P<0.01). Conclusions: Arnebia root oil can promote wound healing of rats with full-thickness skin defect, which may relate to increasing expressions of VEGF and bFGF.

[CD(4+) T lymphocyte responses to anti-retroviral therapy, among HIV/AIDS patients aged 18 and over]

Objective: To compare the differences of CD(4) (+) T lymphocyte (CD(4)) counts between patients aged 18 and over, to explore the effect of age on treatment, 36 months after having received the China National Free AIDS Antiretroviral Treatment on HIV/AIDS. Methods: Through the National ART Information Ssystem, we selected those HIV/AIDS patients who initiated the ART 36 months after the ART, between January 1, 2010 and December 31, 2012 in Guangzhou, Liuzhou and Kunming. Patients were divided into age groups as 18-49, 50-59 and 60 or over year olds, at the baseline of treatment. Under different levels of baseline CD(4) counts, we chose the baseline and different time-point of CD(4) counts as dependent variables, applied mixed linear model to analyze the effects of age, viral suppression, gender, baseline CD(4)/CD(8) ratio and initial treatment regimen. Results: A total of 5 331 HIV/AIDS patients were recruited. No differences were found on age group ratios between different levels of baseline CD(4) counts. At the level of baseline CD(4)<200 cells/μl, both the 50-59 and 60 or above years old groups had lower CD(4) counts than the 18-49 year-old group, within 36 months after the initiation of ART. However, at the baseline CD(4) level of 200-350 cells/μl, no significant differences on CD(4) counts between the 50-59 year-old and 18-49 year-old groups were noticed. CD(4) counts seemed lower in the 60 and above year-old group than in the 18-49 year-old group. Conclusion: Age might serve as an influencing factor on CD(4) counts within 36 months after the initiation of ART, suggesting that earlier initiation of ART might be of help to the recovery of immune function in the 50-59 year-old group.

[Factors associated with adherence of highly active antiretroviral therapy among 386 HIV/AIDS patients in 3 provinces of China]

OBJECTIVE

To investigate adherence and the influence factors among patients who are on antiretrovirus therapy (ART) of 3 provinces in China.

METHODS

This study selected 18-year-old and older AIDS patients as the survey objects who initiated anti-retrovirus therapy between April and September of 2014 and kept on the treatment for one year in Yunnan,Sichuan,and Hu'nan province. Information of demography, treatment and social support was collected by questionnaires. Adopt SSRS questionnaire to calculate the information of objective support, subjective support and utilization of social support. χ(2) test and logistic regression were performed to examine relationships between factors and adherence.

RESULTS

A total of 386 patients with medication were investigated. Among them, there were 365 (94.6%) cases who were compliant to the ART, and 357 (92.5%) cases can take their pills on time, and 29 (7.5%) cases take their medication in excess of the prescribed time more than two hours. Social support score was 27.2 ± 7.3, including objective support score (5.6 ± 2.7), subjective support score (16.1 ± 4.8), and utilization of social support (5.5 ± 1.9). Multivariate logistic regression analysis revealed that adherence was significantly associated with the correct cognition of medication (OR (95%CI): 3.24 (1.17-9.00)), the self-awareness of the drug regimen was not complexity (OR (95%CI): 9.34 (3.27-26.68)), taking medication 1 time a day (OR (95%CI): 4.00 (1.35-11.84)), and the batter utilization of social support (OR (95%CI): 1.49 (1.06-2.01)). Married/cohabiting or farmers tend to be nonadherenced, while the OR (95%CI) was 0.24 (0.08-0.67) and 0.23 (0.08-0.69), respectively.

CONCLUSION

The patients among these provinces were compliant to the ART, and most of them can take their pills on time. The social support score of these patients was lower than normal person. Participants who have correct cognition of medication, thinking their drug regimen was not complexity; Taking medication 1 time a day or have high level of utilization of social support showed a significantly higher level of self-reported adherence.

[Fine needle aspiration cytology of thyroid nodules: a cytopathologic study of 2 043 cases]

OBJECTIVE

To evaluate the clinical value of thyroid fine needle aspiration cytology(FNAC) and the Bethesda system for reporting thyroid cytopathology(TBSRTC).

METHODS

FNAC was performed for 2 043 cases and cytopathological data were retrospectively analyzed. Cytopathological diagnoses according to TBSRTC were classified as non-diagnostic, benign, atypia of undetermined significance/follicular lesion of undetermined significance(AUS/FLUS), follicular neoplasm/suspicious for follicular neoplasm(FN/SFN), suspicious for malignancy(SM) and malignancy. The results of 234 FNAC samples in which surgery was performed were compared with the histological diagnoses.

RESULTS

Of the 2 043 FNAC samples, 15.7%(320/2 043)were non-diagnostic, 51.2%(1 047/2 043)were benign, 16.6%(339/2 043) were AUS/FLUS, 2.3%(46/2 043)were FN/SFN, 8.6%(176/2 043)were SM and 5.6%(115/2 043)were malignant. In 234 cases, there was follow-up histology. Rates of malignancy were as follows: non-diagnostic, 18.2%(2/11); benign(2.2%, 1/45); AUS/FLUS(25.6%, 10/29); FN/SFN(12.1%, 10/39); SM(91.8%, 56/61); malignant(100.0%, 45/45). The sensitivity, specificity, false positive rate, false negative rate and overall accuracy of FNAC in the diagnosis of thyroid nodules was 87.1%(101/116), 95.3%(102/107), 4.7%(5/107), 12.9%(15/116), 91.0%(203/223).

CONCLUSIONS

FNAC is a reliable diagnostic method for evaluation of thyroid disease. TBSRTC is a accurate and effective reporting system for cytopathological diagnoses, so it is worthy of being widely popularized in clinical application.

Microinjection of salusin-beta into the nucleus tractus solitarii inhibits cardiovascular function by suppressing presympathetic neurons in rostral ventrolateral medulla in rats

Salusin-beta is newly identified bioactive peptide of 20 amino acids, which is widely distributed in hematopoietic system, endocrine system, and the central nervous system (CNS). Although salusin-beta extensively expressed in the CNS, the central cardiovascular functions of salusin-beta are unclear. Our main objective was to determine the cardiovascular effect of microinjection of salusin-beta into the nucleus tractus solitarii (NTS) in anesthetized rats. Bilateral or unilateral microinjection of salusin-beta (0.94-94 microg/rat) into the NTS dose-dependently decreased blood pressure and heart rate. Bilateral NTS microinjection of salusin-beta (9.4 microg/rat) did not alter baroreflex sensitivity. Prior application of the glutamate receptor antagonist kynurenic acid (0.19 microg/rat, n=9) into the NTS did not alter the salusin-beta (9.4 microg/rat) induced hypotension and bradycardia. However, pretreatment with the GABA receptor agonist muscimol (0.5 ng/rat) within the rostral ventrolateral medulla (RVLM) completely abolished the hypotension (-14+/-5 vs. -3+/-5 mm Hg, P<0.05) and bradycardia (-22+/-6 vs. -6+/-5 bpm, P<0.05) evoked by intra-NTS salusin-beta (9.4 microg/rat). In addition, we found that vagotomy didn't influence the actions of salusin-beta (9.4 microg/rat) in the NTS. In conclusion, our present study shows that microinjection of salusin-beta into the NTS significantly produces hypotension and bradycardia, presumably by suppressing the activities of presympathetic neurons in the RVLM.

Analytical criterion for amplitude death in nonautonomous systems with piecewise nonlinear coupling

We investigate the amplitude death phenomenon in a nonautonomous chained network with complicated piecewise nonlinear coupling functions. An analytical criterion for the boundary of the amplitude death region is derived by using the average method. The mechanism of the amplitude death in the nonautonomous networks is very different from that of autonomous systems and rapid dynamic transitions could halt the amplitude death. Numerical verifications are carried out to check jump transitions among different solution branches and further confirm the correctness of the theoretical results.

Efficacy of gradual pressure-decline compressing stockings in Asian patients with lower leg varicose veins: analysis by general measurements and magnetic resonance image

AIM

Most applications of gradual pressure-decline compressing stockings (GPDCS) are used in the United States and Western European countries, with over a decade of clinical experiments. Up to know, there is no standard establishment of gradual pressure-decline compressing stockings for Asian patients with venous insufficiency and varicose vein formations.

METHODS

We collected data on volunteer candidates of varicose vein for general measurements and assessments and magnetic resonance imaging (MRI) by non-contrast enhanced MRV techniques, and for post processing data analysis.

RESULTS

Clinical use of GPCDS provide a mild to moderate improvement in the varicose vein conditions of patients with deep venous insufficiency by improving their deep vein circulation, by general measurements; recording major symptoms and complaint; comfort and stretching/flexibility to the candidates after using GPDCS; and area changes/flow velocity changes/available hemoglobin changes in deep veins monitored by MRI.

CONCLUSION

The benefits and data collected in these results may help in developing compression stockings standards in Taiwanese and Asian countries, and to establishing criterias for product sizes, compression levels, and related parameters.

Hepatitis B surface antigen-antibody interactions studied by optical tweezers

The protein-protein interactions between hepatitis B surface antigen (HBsAg) and its antibodies (anti-HBs) were studied by measuring the binding force between microspheres coated with such proteins using optical tweezers. The interaction force between the protein-coated microspheres was found to be strongly influenced by the acidity of the surrounding liquid medium, as well as the experimental temperature, and it reaches a maximum value at around pH 7.5 and temperature around 37°C. By measuring the protein distribution on the surfaces of the microspheres and their contact areas using scanning electron microscopy, the specific binding force between an HBsAg and anti-HBs protein pair is estimated to be around 4.8 pN at the optimum pH value and temperature at an applied loading rate of around 1 pN/s.

Effect of posture positions on the evaporative resistance and thermal insulation of clothing

Evaporative resistance and thermal insulation of clothing are important parameters in the design and engineering of thermal environments and functional clothing. Past work on the measurement of evaporative resistance of clothing was, however, limited to the standing posture with or without body motion. Information on the evaporative resistance of clothing when the wearer is in a sedentary or supine posture and how it is related to that when the wearer is in a standing posture is lacking. This paper presents original data on the effect of postures on the evaporative resistance of clothing, thermal insulation and permeability index, based on the measurements under three postures, viz. standing, sedentary and supine, using the sweating fabric manikin-Walter. Regression models are also established to relate the evaporative resistance and thermal insulation of clothing under sedentary and supine postures to those under the standing posture. The study further shows that the apparent evaporated resistances of standing and sedentary postures measured in the non-isothermal condition are much lower than those in the isothermal condition. The apparent evaporative resistances measured using the mass loss method are generally lower than those measured using the heat loss method due to moisture absorption or condensation within clothing. STATEMENT OF RELEVANCE: The thermal insulation and evaporative resistance values of clothing ensembles under different postures are essential data for the ergonomics design of thermal environments (e.g. indoors or a vehicle's interior environment) and functional clothing. They are also necessary for the prediction of thermal comfort or duration of exposure in different environmental conditions.

Microarray analysis of multiple candidate genes and associated plasma proteins for nephropathy secondary to type 2 diabetes among Chinese individuals

AIMS/HYPOTHESIS

Evolving research suggests that common and rare alleles jointly constitute the genetic landscape of complex disease. We studied the association between 43 pathway-related candidate genes with 'intermediate phenotype' (i.e. corresponding plasma protein) and diabetic nephropathy in a customised microarray of 1,536 SNPs.

METHODS

In this case-control study of type 2 diabetic Chinese individuals with and without diabetic nephropathy, cases (n = 545) were defined on the basis of a spot urinary albumin/creatinine ratio (ACR) > 113 mg/mmol; the value for controls (n = 503) was ACR < 3.3 mg/mmol. Genotyping was performed using Illumina GoldenGate assay.

RESULTS

No single nucleotide polymorphism (SNP) remained significant in single locus analysis after correction for multiple testing. Therefore, we explored the best approximately 1% SNPs. Of these 13 SNPs, four clustered to a 5' end NADPH oxidase homologue 4 (NOX4) haplotype (GGCC frequency = 0.776) with estimated OR for diabetic nephropathy of 2.05 (95% CI 1.04-4.06) (heterozygous) and 2.48 (1.27-4.83) (homozygous) (p = 0.0055). The haplotype was correlated with plasma Cu/Zn superoxide dismutase (SOD) concentration, suggesting increased oxidative burden. Endothelin-1 SNP (rs1476046G>A, frequency = 0.252) was correlated with plasma C-terminal pro-endothelin-1 concentrations with an estimated OR for diabetic nephropathy of (heterozygous) 1.26 (0.96-1.66) and (homozygous) 1.87 (1.13-3.12) (p = 0.0072). Nitric oxide synthase 1 (NOS1) 5' haplotype (TGTC frequency = 0.38) also revealed a suggestive association with diabetic nephropathy: heterozygous 1.26 (0.95-1.67), homozygous 1.57 (1.04-2.35) (p = 0.0073). A rare NADPH oxidase homologue 1 (NOX1)-coding non-synonymous SNP (Arg315His, frequency = 0.006) was found exclusively among cases.

CONCLUSIONS/INTERPRETATION

Our preliminary observations suggest that common haplotypes from NOX4 and endothelin-1 SNP correlated with plasma Cu/Zn SOD and C-terminal pro-endothelin-1 concentrations, respectively, and might have conferred diabetic nephropathy susceptibility. Common NOS1 and rare NOX1 variants also revealed a suggestive association with diabetic nephropathy. Future studies to validate our observation are needed.

First Report of Rhizoctonia Blight of a Coastal Redwood Tissue-Culture-Derived Saplings Caused by Rhizoctonia solani AG-IV in Taiwan

Coastal redwood (Sequoia sempervirens (D. Don) Endl.) is native to North America. This tall tree species is used for forestation and lumber; its wood is also used for furniture, its burls for art ware, and its bark for fuel, insulation, and mulch. In August 2005, an instance of wilt was observed among 2-year-old tissue-culture-cloned plants (2) in the Sitou Forest of central Taiwan. Essentially, all plants were infected. The leaves or stems near the ground were affected first, but the wilt soon spread over the entire plant with the leaves becoming grayish brown and water soaked, and then wilting, drying, and finally defoliation occurred. Aerial hyphae were present over the affected areas, aerial mycelium was cob-web-like, hyaline, later becoming slightly brown. Hyphae were 6.5 to 10.4 μm wide with right-angle branching and septal constriction at their bases. Sclerotia were hemispherical, subglobose, to irregular in shape, 1 to 2 mm, and brown. The perfect stage of the fungus was not found. The fungus was identified as Rhizoctonia solani Kühn (3). Vegetative cells were stained with alkaline safranin solution and identified as multinucleate (1). Portions of the stem that displayed symptoms, together with adjacent healthy tissue, were disinfested for 1 min in 0.5% NaOCl and plated on to potato-dextrose agar (PDA) (Merck, Darmstadt, Germany) supplemented with 100 mg/L of ampicillin (Sigma, St. Louis, MO). Single hyphal tips were transferred to PDA and two isolates were established as pure cultures. On the basis of hyphal anastomosis with AG-IV tester isolates (exfop234, exfop241, and exfop250) (1), the fungus was identifed as R. solani AG-IV. Pathogenicity of the fungal isolates was confirmed by inoculating 2-month-old tissue-culture-derived S. sempervirens plants that were grown in pots and incubated in a growth chamber maintained at 28°C with a relative humidity above 95%. Inoculum consisted of a single mycelial 5-day-old 0.5-cm disc grown on PDA of the pathogen placed on the soil surface touching the base of each plant. Four plants were inoculated with mycelium and the four control plants were noninoculated. Inoculated plants wilted gradually over 4 days and all plants developed severe stem rot and were dead in 6 days, whereas control plants remained symptomless. The Rhizoctonia solani AG-IV was reisolated from all inoculated plants. This fungus has been observed to cause disease in many species of plants (4), but to our knowledge, this is the first report of Rhizoctonia blight of coastal redwood tissue-culture-derived saplings caused by Rhizoctonia solani AG-IV in Taiwan. References: (1) T. T. Chang. Taiwan J. For. Sci. 12:47, 1997. (2) L. C. Huang et al. Plant Physiol. 98:166, 1992. (3) B. Sneh et al. Identification of Rhizoctonia species. The American Phytopathological Society, St. Paul, MN, 1991. (4) S. T. Su et al. List of Plant Diseases in Taiwan. The Phytopathological Society of the Republic of China, 2002.

Reuse potential analysis on WWTP effluent of industrial parks in Taiwan

This study examined the reuse potential of the effluents discharged from several unified wastewater treatment plants (WWTPs) of industrial parks in Taiwan, with designed capacity exceeding 10,000 CMD. Parameters were selected based on the relevant reuse purposes. The "potential recycling percentage", R of the WWTP effluent was defined as the maximal percentage of pure water extractable by the "ideal reverse osmosis module" while the RO retentate still met local effluent standards and required no treatment. The analytical results demonstrated that the WWTP effluents had potential for recycling. A pilot plant was installed in one of the WWTPs. The treatment process included a sand filter, an ultrafiltration unit (UF) and a reverse osmosis module (RO). Results of this study demonstrated that the production quantity and quality are stable and appropriate for various purposes, including both industrial and domestic applications.

Relationship between common functional polymorphisms of the p22phox gene (-930A > G and +242C > T) and nephropathy as a result of Type 2 diabetes in a Chinese population

OBJECTIVE

Genetic determinants are important in diabetic nephropathy (DN). Oxidative stress has also emerged as an important pathogenic factor in DN and vascular NADH oxidase is a major source of reactive oxygen species (ROS). Previous small studies reported a strong but contradictory association between functional genetic variation of p22(phox), an important subcomponent of NADH oxidase, and DN. We investigated the association between two common functional single nucleotide polymorphisms (SNPs) (-930 A > G and +242 C > T) and DN in a much larger group of Chinese patients with Type 2 diabetes mellitus (T2DM).

RESEARCH DESIGN AND METHODS

Case-control study of Chinese subjects with long-standing T2DM (> 10 years). Cases (n = 306) were subjects with a spot urinary albumin : creatinine ratio (ACR) of > 113 mg/mmol or elevated serum creatinine. Control subjects (n = 306) had ACR < 3.3 mg/mmol and normal serum creatinine. Genotyping was carried out by standard PCR and restriction fragment length polymorphism analysis.

RESULTS

Gender distribution, age, duration of diabetes and HbA(1c) were similar in cases and control subjects. Distribution of genotypes in the control subjects for both SNPs was consistent with the Hardy-Weinberg equilibrium. Distribution of genotypes did not differ significantly between cases and control subjects for both polymorphisms-+2424C > T: cases CC 84.6%, CT 15.0%, TT 0.4% and control subjects CC 87.6%, CT 11.8%, TT 0.6% (P = 0.45); -930 A > G: cases AA 40.5%, AG 41.8%, GG 17.7% and control subjects AA 38.2%, AG 49.0%, GG 12.8% (P = 0.12). Distribution of alleles was also similar-+2424 C > T: cases C 92.2%, T 7.8% and control subjects C 93.5%, T 6.5% (P = 0.66); -930 A > G cases A 61.4%, G 38.6% and control subjects A 62.7%, G 37.3% (P = 0.38). We estimated that our study has approximately 80% power to detect a relative risk of 1.65 (for +242 C > T) and 1.35 (for -930 A > G) conferred by the minor allele, respectively.

CONCLUSIONS

In contrast with previous small studies, our data suggest that these SNPs do not confer significantly increased susceptibility to DN secondary to T2DM in Chinese subjects.

A combined phage display ScFv library against Myxobolus rotundus infecting crucian carp, Carassius auratus auratus (L.), in China

Immunological methods have been developed for the diagnosis of Myxobolus rotundus but their use has been limited for the prevention and therapy of this serious parasitic pathogen. Phage display antibody libraries are a powerful technique for the development of antibodies to molecules of interest and have advantages over traditional hybridroma approaches. In the present study, four antigen fractions related to M. rotundus were prepared and a combined phage display single-chain antibody fragments (ScFv) library was constructed against this parasite. Preliminary analysis indicated that a combined antibody library of about 2.08 x 10(5) individual clones and high diversity was generated. After four rounds of screening (bio-panning) against soluble spore protein prepared from lysed, intact, mature M. rotundus spores, a strain monoclonal phage display ScFv, termed pCAN-6H9, with better affinity, was isolated. The pCAN-6H9 gene fragment was sequenced and analysed. The specificity of pCAN-6H9 was further demonstrated by dot-blot. In competition enzyme-linked immunosorbent assay, both the original and enriched phage-displayed ScFv repertoire showed significant inhibition of mouse anti-M. rotundus serum binding to coated antigen, while the inhibition rate of monoclonal pCAN-6H9 phage particles was only 11.83%.

Modulation of inactivation by mutation N588K in KCNH2: A link to arrhythmogenesis in short QT syndrome

OBJECTIVE

Short QT syndrome (SQTS) is characterized by ventricular arrhythmias and sudden death. One form of SQTS is caused by mutation N588K in human ether-a-go-go-related gene (HERG). In this study we sought to determine the potential role of N588K in arrhythmias.

METHODS

We measured the characteristics of HERG current generated by wild-type (WT) KCNH2 and the N588K mutant channel expressed in mammalian TSA201 cells.

RESULTS

Whole-cell patch-clamp recordings of WT HERG currents showed the usual rapid onset of inactivation (rectification) at potentials more positive than +10 mV. In contrast, N588K currents rectified at potentials over +80 mV. Over the physiological range of potentials, N588K currents do not inactivate. During an action potential clamp, WT currents displayed a "hump" like waveform with slow activation kinetics and a rapid increase during phase 3 repolarization. In contrast, N588K currents were proportional to the amplitude of the action potential and displayed a dome-like configuration and a much larger current during the initial phases in the ventricle. Purkinje cell action potentials display a more negative phase 2 repolarization than the ventricle and elicited much smaller WT and N588K currents of similar amplitudes.

CONCLUSIONS

Physiologically the N588K mutation abolishes rectification of HERG currents and specifically increases I(Kr) in the ventricle with minimal effects on the Purkinje fiber action potential duration. Such preferential prolongation may explain the separation of the T and U waves observed in the ECG of SQTS patients and lead to re-excitation of the ventricle endocardium.

Emergency management and infection control in a radiology department during an outbreak of severe acute respiratory syndrome

The World Health Organization classified Taiwan as a serious epidemic-stricken area when the extent of severe acute respiratory syndrome (SARS) in Taiwan became clear. As of 11 July 2003, 671 probable SARS cases had been identified in Taiwan and 7 healthcare workers had died from the disease. Radiographers were easily infected by SARS because they had close contact with suspected or probable cases while conducting chest X-ray examinations. Three radiographers had been infected by the end of May 2003. Because of the impact of SARS on the Radiology Department, the department established a SARS emergency infection control team and re-designed the department's infection-control and emergency-management procedures based on the concept of risk-grade protection. This effort included installing a radiographic room at the fever-screening station, re-allocating human resources in the Radiology Department, training the department staff in infection control, and drafting new operational procedures for radiographers conducting X-ray examinations on SARS patients. The goal of this program was to reduce the infection rate and distribute materials efficiently in the department. This article introduces the emergency-management procedure of the Radiology Department during the SARS outbreak and the infection-protection experience of the department staff.

Compaction mechanism and tablet strength of unlubricated and lubricated (silicified) microcrystalline cellulose

This paper describes the differences in compaction properties between microcrystalline cellulose (MCC) and microcrystalline cellulose co-processed with colloidal silicon dioxide (SMCC). The different compaction parameters are not only compared for the pure materials, but also for the lubricated powders with magnesium stearate. Neither magnesium stearate, nor colloidal silicon dioxide, facilitates extensively the densification of (silicified) microcrystalline cellulose during compaction. The difference in tablet relaxation of MCC and SMCC indicates a small negative effect of colloidal silicon dioxide on the interparticle bonding strength of unlubricated MCC. However, for lubricated MCC a larger increase in tablet relaxation at a high compression speed was found than for lubricated SMCC tablets. Accordingly, the decrease in tablet strength was larger for the MCC tablets than for the SMCC tablets when lubrication was applied. The examination of the tablet strengths of tablets compressed from physical mixtures of MCC with increasing concentrations of colloidal silicon dioxide proved the slightly negative influence of silicon dioxide on the tablet strength of unlubricated MCC tablets and the positive effect of colloidal silicon dioxide addition on the tensile strength of lubricated MCC tablets. Co-processing of MCC with colloidal silicon dioxide showed no extra contribution on the tablet strength of lubricated tablets above the physical mixtures. The interactions between the different materials were further supported by the interaction parameters based on partial solubility parameters.

Humoral immune responses of the grouper Epinephelus akaara against the microsporidium Glugea epinephelusis

The humoral immune responses of grouper Epinephelus akaara to a natural infection with Glugea epinephelusis was studied by ELISA utilizing intact mature spores as the coated antigen. Results showed that a specific humoral immune response was elicited, but the intensity of infection (in terms of the number of cysts) was not related to the antibody level in naturally infected hosts. The differences in the antigenicity of intact mature spores and soluble spore proteins derived from cracked mature spores were also analyzed. Results suggested that similar antigen epitopes existed between the 2 groups. Additionally, antigen component patterns and the distribution of antigen with immunogenicity were investigated by using the western blot and the immunofluorescent antibody technique (IFAT). The new parasitic microsporidium has specific polypeptide patterns comparable to the reported fish microsporidians. The main antigenic substances are concentrated on the surface of spores, and are mostly located on the anterior and posterior end of the spore bodies. Most surface components of the G. epinephelusis spores are soluble. The potential role of the surface components in initiating infection was also discussed.

Molecular orientation of evaporated pentacene films on gold: alignment effect of self-assembled monolayer

Pentacene films deposited on self-assembled monolayers (SAMs) bearing different terminal functional groups have been studied by reflection-absorption IR, grazing angle XRD, NEXAFS, AFM, and SEM analyses. A film with pentacene molecules nearly perpendicularly oriented was observed on Au surfaces covered with an SAM of alkanethiol derivative of X-(CH2)(n)-SH, with X = -CH(3), -COOH, -OH, -CN, -NH(2), C(60), or an aromatic thiol p-terphenylmethanethiol. On the other hand, a film with the pentacene molecular plane nearly parallel to the substrate surface was found on bare Au surface. A similar molecular orientation was found in thinner ( approximately 5 nm) and thicker (100 nm) deposited films. Films deposited on different surfaces exhibit distinct morphologies: with apparently smaller and rod-shaped grains on clean bare Au surface but larger and islandlike crystals on SAM-modified surfaces. X-ray photoemission electron microscopy (X-PEEM) was used to analyze the orientation of pentacene molecules deposited on a SAM-patterned Au surface. With the micro-NEXAFS spectra and PEEM image analysis, the microarea-selective orientation control on Au was characterized. The ability to control the packing orientation in organic molecular crystals is of great interest in fabricating organic field effect transistors because of the anisotropic nature of charge transport in organic semiconducting materials.

Contribution of neuronal sodium channels to the cardiac fast sodium current is greater in dog heart Purkinje fibers than in ventricles

OBJECTIVE

To determine the presence and the potential contribution of neuronal sodium channels to dog cardiac function.

METHODS

We used a combination of electrophysiological (patch clamp), RT-PCR, biochemical and immunohistochemical techniques to identify and localize neuronal Na(+) channels in dog heart and determine their potential contribution to the fast sodium current.

RESULTS

In all cardiac tissues investigated, Na(v)1.1, Na(v)1.2 and Na(v)1.3 transcripts were detected. In immunoblots, we found Na(v)1.1 and Na(v)1.2 proteins in the ventricle (V) and in Purkinje fibers (PF). Na(v)1.3 immunoblots suggested strong proteolytic activity against this isoform in the heart. Na(v)1.6 was not found in any of the tissues tested. Confocal immunofluorescence on cardiac myocytes showed that Na(v)1.1 was predominantly localized at the intercalated disks in V and PF and around the nucleus (V). Na(v)1.2 was only present at the Z lines (V). Consistent with the immunoblot data, an intense but diffuse intracellular staining was observed for Na(v)1.3. Na(v)1.6 fluorescence staining was faint and diffuse. Surprisingly, immunoblots indicated the presence of two Na(v)beta 2 variants: a 42-kDa protein that co-localized with Na(v)1.2 at the Z lines in V and a 34-kDa protein that co-localized with Na(v)1.1 at the intercalated disks in PF. In agreement with the biochemical data, electrophysiological results suggest that neuronal sodium channels generate 10+/-5% and 22+/-5% of the peak sodium current in dog ventricle and Purkinje fibers, respectively.

CONCLUSIONS

Our results suggest that neuronal NaChs are more abundant in Purkinje fibers than in ventricles, and this suggests a role for them in cardiac conduction.

[Expression and immunocompetence characterization of Plasmodium falciparum lactate dehydrogenase]

OBJECTIVE

To express lactate dehydrogenase (LDH) gene of Plasmodium falciparum FCC1/HN in the E. coli TG1 and analyse its immunocompetence.

METHODS

The LDH gene of the P. falciparum was specifically amplified by polymerase chain reaction, and the recovered gene fragment was cloned into pGEX-4T-1 vector for expression of fusion protein with glutathione S-transferase(GST). The recombinant plasmid was transformed into the E. coli TG1. Four mice (Kunming strain) were immunized with purified expressed protein(antigen) and the polyclonal antibodies were collected. The immunocompetence of recombinant protein was analysed by ELISA and Western-blot.

RESULTS

The LDH gene of P. falciparum was successfully expressed in the E. coli TG1. The expressed protein exhibited a specific reaction with immune sera obtained from rabbits immunized with P. falciparum. The specific humoral responses were induced in mice and the titer of the specific antibody was 1:16 by two-dimensional diffusion assay.

CONCLUSION

The LDH gene of P. falciparum has been successfully expressed in the E. coli TG1 and the expressed protein has high antigencity.

[Preparation and characterization of McAbs against lactate dehydrogenase of Plasmodium falciparum]

OBJECTIVE

To prepare and characterize the monoclonal antibodies(McAbs) against lactate dehydrogenase of the Plasmodium falciparum(LDHp).

METHODS

BALB/c mice were immunized with purified recombinant LDHp and McAbs against LDHp were prepared according to the protocol of hybridoma technique. The McAbs were characterized by ELISA and Western blot analysis.

RESULTS

Two McAbs against LDHp antigen were obtained. Both McAbs were IgG2b. The titer of two McAbs(2A5, 1H10) in the ascites was 1:25,600 and 1:12,800, and in supernatant were 1:512,1:256 respectively. The result of ELISA indicated that two McAbs reacted only with P. falciparum, and did not react with normal human red blood cells, P. vivax, Toxoplasma gondii, Schistosoma japonicum. It is recognized 33 kDa protein which was defined as LDHp by Western blot analysis.

CONCLUSION

Two hybridoma cell lines secreting high titer of McAbs against LDHp with high specificity were established.

Estimation of percolation flux from borehole temperature data at Yucca Mountain, Nevada

Temperature data from the unsaturated zone (UZ) at Yucca Mountain are analyzed to estimate percolation-flux rates and overall heat flux. A multilayer, one-dimensional analytical solution is presented for determining percolation flux from temperature data. Case studies have shown that the analytical solution agrees very well with results from the numerical code, TOUGH2. The results of the analysis yield percolation fluxes in the range from 0 to 20 mm/year for most of the deep boreholes. This range is in good agreement with the results of infiltration studies at Yucca Mountain. Percolation flux for the shallower boreholes, however, cannot be accurately determined from temperature data alone because large gas flow in the shallow system alters the temperature profiles. Percolation-flux estimates for boreholes located near or intersecting major faults are significantly higher than those for other boreholes. These estimates may be affected by gas flow in the faults.

Coordinated down-regulation of KCNQ1 and KCNE1 expression contributes to reduction of I(Ks) in canine hypertrophied hearts

OBJECTIVE

In animal models of hypertrophy, electrical remodeling giving rise to QT prolongation occurs rapidly and is associated with the development of torsade de pointes (TdP) arrhythmias and sudden death. Chronic AV block (CAVB)-induced hypertrophy in dogs has been associated with a reduction in the slow component (I(Ks)) of the delayed rectifier potassium current (I(K)), which contributes to a prolongation of ventricular repolarization, the development of an acquired form of long QT, and the substrate for triggered activity and TdP. The present study was designed to probe the molecular basis for the decrease in I(Ks) by studying the characteristics of KCNE1 and KCNQ1, the putative genes responsible for formation of the channel.

METHODS AND RESULTS

Using a combination of Northern blot, competitive multiplex PCR and immunoblot assays, we found that CAVB reduces KCNE1 and KCNQ1 RNA in the canine ventricles by 70 and 80%, respectively. Protein levels of KCNE1 and KCNQ1 were reduced by 60 and 50%, respectively. We also demonstrate at the molecular level the basis for inter-ventricular difference in I(Ks) density previously reported in hearts of normal dogs and show the basis for reduction of this difference in the CAVB dog.

CONCLUSIONS

Our results indicate that the CAVB-induced reduction in I(Ks) is due to a down-regulation of KCNE1 and KCNQ1 transcription. The data suggest that electrical remodeling of the cardiac ventricle during hypertrophy involves regulation of the gene expression through modulation of transcriptional and translational regulatory pathways. The reduction in KCNE1 and KCNQ1 expression increases the dependence of ventricular repolarization on the rapid component of I(K) and may potentiate the action of Class III antiarrhythmic agents.

Dimensional analysis for establishing the testing criteria of kinetic study with respirometry

The kinetic study of a microbial system requires the determination of kinetic parameters under a set of operating variables. Previous researchers indicated that initial conditions, such as S0/X0 and S0/KS may influence the reliability of the parameter estimation. However, little study has been done to identify the sensitivity of system variables to the parameter estimation. This study proposes a novel dimensional analysis and identifies six dimensionless groups: mu(m)/fw, kd/fw, Yg, S0/KS, KS/S0, and 1/(fw theta(c) - 1). By incorporating the SP-moving algorithm proposed by Wu and coworkers in 2001, an algorithm was proposed in this study to perform a sensitivity analysis on the six dimensionless groups. Results of this analysis reveal that S0/X0 is more sensitive than S0/KS, as also evidenced by the fact that gross growth yield (Yg) is sensitive and affecting S0/X0. The analysis also suggests that the theta(c)-based wasting frequency (fw theta(c)) is more sensitive than the daily wasting frequency (fw). A critical minimum value of 1.3 for S0/X0 and a maximum value of 0.1 for S0/KS were suggested to establish the testing criteria for the kinetic study under the respirometric conditions.

Functional expression of GFP-linked human heart sodium channel (hH1) and subcellular localization of the a subunit in HEK293 cells and dog cardiac myocytes

Recent evidence suggests that biosynthesis of the human heart Na+ channel (hH1) protein is rapidly modulated by sympathetic interventions. However, data regarding the intracellular processing of hH1 in vivo are lacking. In this study we sought to establish a model that would allow us to study the subcellular localization of hH1 protein. Such a model could eventually help us to better understand the trafficking of hH1 in vivo and its potential role in cardiac conduction. We labeled the C-terminus of hH1 with the green fluorescent protein (GFP) and compared the expression of this construct (hH1-GFP) and hH1 in transfected HEK293 cells. Fusion of GFP to hH1 did not alter its electrophysiological properties. Confocal microscopy revealed that hH1-GFP was highly expressed in intracellular membrane structures. Immuno-electronmicrographs showed that transfection of hH1-GFP and hH1 induced proliferation of three types of endoplasmic reticulum (ER) membranes to accommodate the heterologously expressed proteins. Labeling with specific markers for the ER and the Golgi apparatus indicated that the intracellular channels are almost exclusively retained within the ER. Immunocytochemical labeling of the Na+ channel in dog cardiomyocytes showed strong fluorescence in the perinuclear region of the cells, a result consistent with our findings in HEK293 cells. We propose that the ER may serve as a reservoir for the cardiac Na+ channels and that the transport from the ER to the Golgi apparatus is among the rate-limiting steps for sarcolemmal expression of Na+ channels.