Monitoring hepatocellular carcinoma using tumor content in circulating cell-free DNA

PURPOSE

To evaluate the utility of tumor content in circulating cell-free DNA (ccfDNA) for monitoring hepatocellular carcinoma (HCC) throughout its natural history.

METHODS

We included 67 hepatitis B virus (HBV)-related HCC patients, of whom 17 had paired pre- and post-treatment samples, and 90 controls. Additionally, in a prospective cohort with HBV surface antigen-positive participants recruited in 2012 and followed up biannually with blood sample collections until 2019, we included 270 repeated samples before diagnosis from 63 participants who later developed HCC (pre-HCC samples). Shallow whole-genome sequencing and the ichorCNA method were used to analyze genome-wide copy number and tumor content in ccfDNA.

RESULTS

High tumor content was associated with advanced tumor stage (P < 0.001) and a poor survival after HCC diagnosis (HR=12.35; 95% confidence interval [CI]=1.413-107.9; P = 0.023). Tumor content turned negative after surgery (P = 0.027), while remained positive after transarterial chemoembolization treatment (P = 0.578). In non-HCC samples, the mean tumor content (±SD) was 0.011 (±0.007) and had a specificity of 97.8% (95%CI=92.2%-99.7%). In pre-HCC samples, tumor content increased from 0.014 in 4 years before diagnosis to 0.026 in 1 year before diagnosis. The sensitivity of tumor content in detecting HCC increased from 22.7% (95%CI=11.5%-37.8%) within one year before diagnosis to 30.4% (95%CI=13.2%-52.9%) at BCLC stage 0/A, 81.8% (95%CI=59.7%-94.8%) at stage B, and 95.5% (95%CI=77.2%-99.9%) at stage C.

CONCLUSIONS

The tumor content in ccfDNA is correlated with tumor burden and may help in monitoring HCC one year earlier than clinical diagnosis and in predicting patient prognosis.

[Clinical application of combination of different types of free perforator flaps in the repair of complex wounds in extremities]

Objective: To investigate the clinical application effects of combination of different types of free perforator flaps in the repair of complex wounds in extremities. Methods: A retrospective observational study was conducted. From January 2018 to June 2022, 11 patients with complex wounds in extremities who met the inclusion criteria was admitted to the Affiliated Hospital of Zunyi Medical University, including 8 males and 3 females, aged 28 to 55 years. The wounds in the upper extremities in 4 cases and in the lower extremities in 7 cases were repaired with different combination of free perforator flaps. After debridement, the wound area was 7.0 cm×6.0 cm-28.0 cm×12.0 cm. A combination of different types of perforator flaps were applied, including the perforator tri-leaf flap of the descending branch of the lateral femoral circumflex artery in 6 cases, the descending branch of lateral femoral circumflex artery combined with oblique branch perforating branch flap in 2 cases, the lobulated flap of the descending branch of the lateral femoral circumflex artery combined with the contralateral medial plantar artery perforator flap in 2 cases, and the bilateral perforator flap of the descending branch of lateral femoral circumflex artery combined with great toe nail flap in 1 case, with the size of a single flap ranged from 2.0 cm×2.0 cm-25.0 cm×6.0 cm. The donor site was repaired by direct suture, skin grafting, or flap transplantation. During free flap transplantation, the flap was cut and split according to the distribution of perforators, and end-to-end or end-to-side anastomosis was performed between the donor area and the recipient area. After surgery, the survival of transplanted flap in the primary recipient site, the occurrence of vascular crisis, the wound healing in the flap donor site, and the survival of transplanted skin or flap in the flap donor site were observed. During follow-up, the blood supply, appearance and texture of the transplanted flap in the primary recipient site were observed; and at the same time, the weight bearing of the plantar receiving area, the presence of sliding, ulcers, and sinus tracts of the flap, and the appearance and function of the hand were observed; the complications in the donor area were observed. Results: After surgery, one patient's transplanted flap in the primary recipient site had vascular crisis but survived after exploration+vein graft bridging; partial necrosis occurred in one lobe of anterolateral thigh lobulated flap transplanted to the primary recipient site in one patient and recovered after dressing change+skin grafting, and the different types of perforator flap transplanted to the primary recipient site in the other 9 patients all survived. After surgery, the wound with direct suture at the donor site healed well, and the skin or flap transplanted to the donor area survived well. During 3-24 months of follow-up, the blood supply, appearance, and texture of the transplanted flap at the primary recipient site were good. In two patients, the anterolateral thigh flap combined with the medial plantar flap were used to repair plantar defects. The plantar receiving area was able to bear weight, and the texture of the flaps in the recipient area was close to the normal plantar skin, without flap sliding, ulcer, or sinus tract formation. In one patient, bilateral anterolateral thigh flap combined with great toe nail flap were used to repair hand combined with soft forearm defect, and the appearance and function of hand, especially thumb were good. Only linear scar was left in the donor site without other obvious complications. Conclusions: The combination of different types of perforator flaps is a reliable clinical method to repair complex wounds in extremities with high safety, good efficacy, and less complications.

Bending effect on the Majorana bound states in planar Josephson junctions

We consider the bending effect on the formation of Majorana bound states (MBSs) in planar Josephson junctions where the normal stripe is tilted in a V shape. Our results show that the MBSs remain robust for moderate bending angles. Beyond some critical angles, the degradation of MBSs can be revealed by its eigenspectrum as well as the Majorana polarization (MP). Our results show that the parameter space of bending angle for robust MBSs can be significantly enlarged by tuning the superconducting phase difference across the Josephson junction. These findings suggest that the interplay of the junction geometry and the device parameters provides richer degree of freedom in designing topological superconducting devices for future applications. The MP analysis is an indispensable tool for characterizing the Majorana states.

Prospective assessment of a nasopharyngeal carcinoma risk score in a population undergoing screening

Despite evidence suggesting the utility of Epstein-Barr virus (EBV) markers to stratify individuals with respect to nasopharyngeal carcinoma (NPC) risk in NPC high-risk regions, no validated NPC risk prediction model exists. We aimed to validate an EBV-based NPC risk score in an endemic population undergoing screening for NPC. This prospective study was embedded within an ongoing NPC screening trial in southern China initiated in 2008, with 51 235 adult participants. We assessed the score's discriminatory ability (area under the receiver-operator-characteristics curve, AUC). A new model incorporating the EBV score, sex and family history was developed using logistic regression and internally validated using cross-validation. AUCs were compared. We also calculated absolute NPC risk combining the risk score with population incidence and competing mortality data. A total of 151 NPC cases were detected in 2008 to 2016. The EBV-based score was highly discriminating, with AUC = 0.95 (95% CI = 0.93-0.97). For 90% specificity, the score had 87.4% sensitivity (95% CI = 81.0-92.3%). As specificity increased from 90% to 99%, the positive predictive value increased from 2.4% (95% CI = 1.9-3.0%) to 12.5% (9.9-15.5%). Correspondingly, the number of positive tests per detected NPC case decreased from 272 (95% CI = 255-290) to 50 (41-59). Combining the score with other risk factors (sex, first-degree family history of NPC) did not improve AUC. Men aged 55 to 59 years with the highest risk profile had the highest 5-year absolute NPC risk of 6.5%. We externally validated the discriminatory accuracy of a previously developed EBV score in a high-risk population. Adding nonviral risk factors did not improve NPC prediction.

Theoretical investigation of the scanning tunneling microscopy of Majorana bound states in topological superconductor vortices

Scanning tunneling microscopy (STM) is an indispensable tool in detecting Majorana bound states (MBSs) in vortices of topological superconductors. By reducing the computational complexity via non-uniform grids, we systematically study the tunnel coupling as well as the temperature dependence of the differential conductance of MBSs in two dimensional devices. Numerical results show that the conductance peak approaches the quantized value 2e ²/h in strong coupling limit at low temperatures which are characteristic features of MBSs. More interestingly, a conductance local minimum in the spatially scanning is observed when the STM tip is placed at the vortex center. The dip structure can be enhanced with increased temperature or enlarged vortex size. We ascribe this observation to the sensitivity of the Andreev reflection processes of carriers at the vortex center where the thermal energy could be comparable to the vanishing pair potential. We also investigate the STM of two-vortex systems where the hybridization of the vortices can lead to oscillatory behavior of the state energy. With small inter-vortex distances, the original MBSs in vortices can merge into topologically trivial states and the conductance peak can be significantly suppressed.

[Application of a new solid adsorbent tube for the determination of three kinds of epoxy eompounds in air]

Objective: To develop a new solid sorbent tube for simultaneously capturing ethylene oxide (EO) , propylene oxide (PO) and epichlorohydrin (ECH) in air, and establish a complete set of method. Methods: In June 2018, EO, PO and ECH in air were captured by the new solid sorbent tube filled with carbon aerogel adsorbent, desorbed with solution of 5% (V/V) methanol-methylene chloride, separated through capillary chromatographic column, and then analyzed by gas chromatography-flame ionization detector. Results: The linear ranges of EO, PO and ECH were 0.24-960.00, 0.60-2384.00 and 0.12-472.40 mg/L respectively, and the related coefficients were between 0.99995-0.99997. The relative standard deviations (RSD) within the group were 1.66%-4.09%, 1.36%-4.43%, and 1.99%-5.65%, respectively, and the RSD between the group were 2.69%-4.95%, 2.77%-5.30%, and 3.27%-6.67%, respectively. The average desorption efficiencies were 88.25%-94.50%, 98.17%-98.60%, and 97.79%-101.04%, respectively. The samples could be stored at 4 ℃ refrigerator for at least 27 days. Conclusion: The newly developed solid sorbent tube filled with carbon aerogel adsorbent and its complete set of gas chromatography method could be used for sampling and quantitative detection of EO, PO and ECH in workplace air.

Incidence and mortality of nasopharyngeal carcinoma: interim analysis of a cluster randomized controlled screening trial (PRO-NPC-001) in southern China

BACKGROUND

Previous mass screening studies have shown that IgA antibodies against Epstein-Barr Virus (EBV) can facilitate early detection of nasopharyngeal carcinoma (NPC), but the impact of EBV-antibody screening for NPC-specific mortality remains unknown.

PATIENTS AND METHODS

A prospective, cluster randomized, controlled trial for NPC screening (PRO-NPC-001) was conducted in 3 selected towns of Zhongshan City and 13 selected towns of Sihui City in southern China beginning in 2008. Serum samples of the screening group were tested for two previously selected anti-EBV antibodies. Subjects with serological medium risk were subsequently retested annually for 3 years, and those with serological high risk were referred to otorhinolaryngologists for diagnostic check-up. An interim analysis was carried out to evaluate the primary end points of the NPC-specific mortality and the early diagnostic rate, and the secondary end point of the NPC incidence, through linkage with the database of Zhongshan City.

RESULTS

Among 70 296 total subjects, 29 413 screened participants (41.8% of the total subjects) in the screening group and 50 636 in the control group, 153 (43.3 per 100 000 person-year), 62 (55.3 per 100 000 person-year) and 99 (33.1 per 100 000 person-year) NPC cases were identified. The early diagnostic rates of NPC were significantly higher in the participants (79.0%, P < 0.0001) and the screening group (45.9%, P < 0.0001) compared with the control group (20.6%). Although no differences were found between NPC-specific mortality of the screening group and the control group [relative risk (RR)= 0.82, 95% confidence interval (CI) 0.37-1.79], lower NPC-specific mortality was noticed among participants from the screening group versus the control group (RR = 0.22, 95% CI 0.09-0.49).

CONCLUSION

IgA antibodies against EBV can identify high-risk population and was effective in screening for early asymptomatic NPC. Although the mortality reduction was not significant in the primary end point, we noted encouraging evidence of a mortality reduction in screening participants in this interim analysis.

CLINICAL TRIAL NUMBER

NCT00941538.

[Simultaneous determination of four kinds methyl acrylate compounds in workplace air]

Objective: To develop a solvent desorption-gas chromatography method for simultaneous determination of methyl methacrylate (MMA) , ethyl methacrylate (EMA) , n-propyl methacrylate (PMA) and butyl methacrylate (BMA) in workplace air. Methods: MMA, EMA, PMA and BMA in workplace air were captured by charcoal tubes and desorbed with carbon disulfide, separated through capillary chromatographic column, and then analyzed by gas chromatography-flame ionization detector. Results: The linear ranges of MMA, EMA, PMA and BMA were 0-8 305.00 mg/L, 0-9 080.50 mg/L, 0-8 899.00 mg/L and 0-8 371.00 mg/L respectively, and the related coefficients were between 0.999 96-0.999 98. The relative standard deviations (RSD) within the group were 0.56%-1.71%, 0.45%-1.65%, 0.51%-1.49% and 0.45%-1.50% respectively, and the RSD between the group were 1.14%-2.79%, 0.79%-2.13%, 0.93%-2.30% and 1.09%-2.84% respectively. The average desorption efficiencies were 95.76%-99.58%, 97.82%-102.28%, 98.55%-102.28%and 98.70%-102.40% respectively. The minimum quantification concentrations were 0.12 mg/m(3), 0.10 mg/m(3), 0.07 mg/m(3) and 0.07 mg/m(3) respectively (3.00 L sample) . The samples could be stored at room temperature for at least 7 days. Conclusion: This method could be used for monitoring of MMA, EMA, PMA and BMA in workplace air.

Quantum interference of Josephson current in topological Anderson insulator junctions

We investigate the critical supercurrent in Josephson junctions consisting of topological Anderson insulators (TAIs) via the Matsubara Green's function formalism. Our numerical results show that the disorder-induced edge states display distinct differences in dominating normal and supercurrent transport in the TAI phase. Unlike the hallmark of the TAI phase which exhibits a quantized conductance plateau, the critical supercurrent over the disorder strength exhibits a peak structure where the maximum value is reached at the weak-disorder boundary of the TAI phase. Although the magnitude of the averaged critical supercurrent is suppressed with increasing disorder strength, periodic oscillations of the supercurrent on an external magnetic flux survive in the TAI phase. These findings indicate that the supercurrent quantum interference effect can be an effective probe in detecting the emergence of disorder-induced edge state in TAIs.

[Clinical effects of superior gluteal artery perforator island flap in repair of sacral pressure ulcer]

Objective: To explore the clinical effects of superior gluteal artery perforator island flap in repair of sacral pressure ulcer. Methods: From May 2012 to May 2017, 20 patients with sacral pressure ulcers (14 males and 6 females, aged 27 to 67 years) were admitted to our department. According to the consensus staging system of National Pressure Ulcer Advisory Panel in 2016, 6 cases were in 3 stages, 14 cases were in 4 stages, with the area of pressure ulcers ranging from 5.0 cm×4.0 cm to 10.0 cm×8.0 cm. After debridement and vacuum sealing drainage, the superior gluteal artery perforator island flaps were used to repair the pressure wounds, with the area of flaps ranging from 6 cm×5 cm to 13 cm×8 cm. The donor sites were sutured directly. The survival of flaps after operation, the healing of wounds, and the follow-up of patients were observed. Results: After surgery, flaps of 20 patients survived well without reoperation. The length of hospital stay of patients was 20 to 40 days, with an average of 25 days. Eighteen patients were followed up for 6 to 24 months, with an average of 12.2 months. The flaps were in good shape and elastic recovery. There were no complications such as seroma or hematoma in the donor sites. Both the patients and family members expressed satisfaction with the shape and texture of the flap and shape of hip. Conclusions: The superior gluteal artery perforator island flap is reliable in blood supply and easy to rotate. The flap can carry a little muscle to increase the anti-infective ability. Moreover, the donor site can be directly sutured with slight damage. Thus, it is one of the good methods for repairing sacral pressure ulcers.

[Effects of combined transplantation of rat Schwann cells and fibroblasts on nerve regeneration of denervated perforator flaps in rats and the mechanism]

Objective: To explore the effects of combined transplantation of the rat Schwann cells and fibroblasts (Fbs) on the nerve regeneration of denervated perforator flaps in rats and the mechanism. Methods: (1) Fbs were isolated from the trunk of 2 Sprague-Dawley (SD) rats embryos of 14-16 days' pregnancy and cultured, and the morphology of the cells was observed. The third passage of cells were used for subsequent experiments. The protein expressions of fibronectin and Ephrin-B2 were observed by immunohistochemical method. The mRNA expression of Ephrin-B2 was detected by real-time fluorescent quantitative reverse transcription polymerase chain reaction (n=3). (2) Schwann cells were isolated from the bilateral sciatic nerves and brachial plexus nerves of 45 SD rats born for 1-3 days and cultured, and the morphology of the cells was observed. The third passage of cells were used for subsequent experiments. The rate of S100 positive cells was detected by immunofluorescence method and flow cytometer, with sample numbers of 9 and 3 respectively. (3) In Dulbecco's modified Eagle medium (DMEM) high glucose medium, 1 mL Fbs and 1 mL Schwann cells both in the concentration of 1×10(5) cells/mL were co-cultured as Schwann cells+ Fbs co-culture group, and 2 mL Schwann cells in the concentration of 1×10(5) cells/mL were cultured alone as Schwann cells alone culture group, with 5 wells in each group. The clusters of Schwann cells in the two groups were observed and counted under inverted phase contrast microscope at post culture hour (PCH) 6 and 24 respectively. The clusters of Schwann cells in Schwann cells+ Fbs co-culture group were observed by immunofluorescence method at PCH 24 too. The protein expressions of EphB2, Sox2, and N-cadherin in Schwann cells of two groups at PCH 24 were detected by Western blotting (n=20). (4) Totally 100 8-week-old male SD rats were selected, and an in situ replanted peritoneal denervated perforator flap was made in each rat. According to the random number table, the rats were divided into simple flap group, Fbs alone transplantation group, Schwann cells alone transplantation group, Schwann cells+ Fbs co-transplantation group, with 25 rats in each group. Flaps of rats in Fbs alone transplantation group and Schwann cells alone transplantation group were injected with 0.4 mL Fb and 0.4 mL Schwann cells respectively (2×10(6) cells each). Flaps of rats in Schwann cells+ Fbs co-transplantation group were injected with 0.4 mL Fbs and Schwann cells mixed cells (totally 2×10(6) cells, cell number ratio: 1∶1), and flaps of rats of simple flap group were injected with the same volume of DMEM high glucose medium. On post injection day (PID) 2, 5, 7, 9, and 14, 5 rats in each group were selected respectively according to the random number table. The flap tissue was collected, and the number, diameter, and arrangement of regenerated nerves were observed by immunofluorescence method. Data were processed with completely random designed t test, analysis of variance for repeated measurement, t test, and Bonferroni correction. Results: (1) The third passage of cells isolated and cultured from the rat embryo trunks were uniform in size and shape, long spindle-shaped, with a large proportion of nuclei. Strong positive expressions of fibronectin and Ephrin-B2 protein in cells were observed, and the mRNA expression of Ephrin-B2 was 0.004 1±0.000 8. The cells were identified as Fbs. (2) After 5 days of culture, the primary cells isolated from the sciatic nerves and brachial plexus nerves of neonatal rats were elongated in cell bodies and grew in nest, fence, or vortex-like shape. The third passage of cells were detected by immunofluorescence method and flow cytometer, and the corresponding S100 positive cell rates were (95.9±1.0)% and (95.8±1.1)% respectively. The cells were identified as Schwann cells. (3) At PCH 6 and 24, the cluster numbers of Schwann cells in Schwann cells+ Fbs co-culture group were significantly higher than those of Schwann cells alone culture group (t=6.500, 10.614, P<0.01). At PCH 24, the Schwann cells in Schwann cells+ Fbs co-culture group aggregated into clusters, Fbs dispersed around the Schwann cell clusters, and the protein expressions of EphB2, N-cadherin, and Sox2 in Schwann cells were significantly higher than those in Schwann cells alone culture group (t=2.975, 19.717, 11.159, P<0.05 or P<0.01). (4) On PID 2, a small number of scattered, disordered, short, and thin nerve fibers were observed in the flap tissue of rats in the four groups. From PID 5 to 14, the number of nerve fibers in the flap tissue of rats of Schwann cells+ Fbs co-transplantation group increased gradually, and the nerve fibers were with long diameter and arranged orderly. The number of nerve fibers in the flap tissue of rats of Schwann cells alone transplantation group increased, but the nerve fibers were with short diameter and arranged disorderly, and the number was smaller than that of Schwann cells+ Fbs co-transplantation group. In simple flap group and Fbs alone transplantation group, the nerve fibers in the flap tissue of rats gradually degenerated with gradually decreased number or even disappeared. Conclusions: The combined transplantation of Fbs and Schwann cells in rats can regulate Schwann cells migration and clustering by activating Ephrin/Eph-Sox2-N-cadherin signaling pathway, thus promoting the orderly nerve regeneration of denervated perforator flaps in rats.

[Effects of lappaconitine on pain and inflammatory response of severely burned rats and the mechanism]

Objective: To explore the effects of lappaconitine (LA) on pain and inflammatory response of severely burned rats and the mechanism. Methods: Forty SD rats were divided into healthy+ normal saline group, sham injury+ normal saline group, pure burn group, burn+ LA group, and healthy+ LA group according to the random number table (the same dividing method below), with 8 rats in each group. Rats in pure burn and burn+ LA groups were inflicted with about 32% total body surface area deep partial-thickness scald (hereinafter referred to as burn) on the back and right hind. Rats in sham injury+ normal saline group were sham injured. Rats in burn+ LA group were intraperitoneally injected with 1 g/L LA solution in the dosage of 4 mL/kg at 2.0 h before injury and post injury hour (PIH) 0 (immediately), 24.0, 48.0, and 72.0. Rats in healthy+ LA group were intraperitoneally injected with LA solution in the same dose at the same time points as above, and rats in healthy+ normal saline and sham injury+ normal saline groups were intraperitoneally injected with normal saline in the dose of 4 mL/kg at the same time points as above. At 1.5 h before injury and PIH 12.5, 24.5, 36.5, 48.5, and 72.5, the paw withdrawal mechanical threshold (PWMT) of injured rats was detected, and their pain behaviors were observed. The same observation and detection were conducted in rats without injury in the two groups at the same time points as above. Another 32 SD rats were divided into normal saline group, trinitrophenyl (TNP)-ATP group, minocyline group, pyridoxal-phosphate-6-azophenyl-2', 4'-disulfonic acid (PPADS) group, with 8 rats in each group, and all the rats were inflicted with the same burn injury as above. At PIH 48.0, rats in normal saline group were intrathecally injected with 10 μL normal saline; rats in TNP-ATP group were intrathecally injected with 10 μL TNP-ATP in the concentration of 30 nmol/μL; rats in minocyline group were intrathecally injected with 10 μL minocyline in the concentration of 5 g/L; rats in PPADS group were intrathecally injected with 10 μL PPADS in the concentration of 10 nmol/μL. The PWMT of rats was detected at 0.5 h before injection and 0.5 h after. At PIH 72.5, the tissue in the dorsal horn of spinal cord of rats in sham injury+ normal saline, pure burn, and burn+ LA groups was harvested to observe the co-expression of P2X(4) receptor and OX42 receptor with immunofluorescent staining and to observe the expression of P2X(4) receptor and count the positive cells with immunohistochemical staining. The venous blood was harvested for determination of serum content of tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β) with enzyme-linked immunosorbent assay. The same observation and determination were conducted in rats without injury in the two groups at the same time point as above. Data were processed with one-way analysis of variance, analysis of variance for repeated measurement, SNK test, paired t test, and Bonferroni correction. Results: (1) There were no abnormal activity in rats of healthy+ normal saline, sham injury+ normal saline, healthy+ LA groups at all time points. Until PIH 72.5, rats in pure burn group were in poor mental state; red and swollen manifestation and blister were observed in burn wounds on the back and right hind; imbalance in gait, lick, bite, and scratch were observed occasionally. Fewer behaviors such as lick, bite, and limp were observed in rats in burn+ LA group than in pure burn group, and the red and swollen manifestation in wounds of rats in burn+ LA group dissipated faster than that in pure burn group. (2) At 1.5 h before injury, there were no significant differences in the PWMT values of rats in healthy+ normal saline, sham injury+ normal saline, pure burn, burn+ LA, and healthy+ LA groups (F=0.106, P>0.05). PWMT values of rats in pure burn group were significantly lower than those in the other 4 groups at all post injury time points (with P values below 0.05). PWMT values of rats in burn+ LA group were significantly lower than those in healthy+ normal saline, sham injury+ normal saline, and healthy+ LA groups at all post injury time points (with P values below 0.05). (3) At 0.5 h before injection, PWMT values of rats in normal saline, TNP-ATP, PPADS, and minocyline groups were close, respectively 15.3±0.8, 15.1±1.0, 15.3±0.9, and 15.6±1.1 (F=0.343, P>0.05). At 0.5 h after injection, PWMT values of rats in normal saline group and PPADS group were respectively 15.2±1.2 and 14.8±1.0, which were significantly lower than 20.8±1.4 and 26.3±1.0 in TNP-ATP group and minocyline group respectively (with P values below 0.05). PWMT values of rats in normal saline and PPADS groups were similar before and after injection (with t values respectively 0.073 and -0.772, P values above 0.05), while those of rats in TNP-ATP and minocyline groups were higher after injection than before injection (with t values respectively -10.180 and -20.813, P values below 0.01). (4) At PIH 72.5, co-expression of P2X(4) receptor and OX42 receptor was observed in a few microglias of rats in healthy+ normal saline, sham injury+ normal saline, and healthy+ LA groups, while co-expression of P2X(4) receptor and OX42 receptor was observed in a large number of microglias of rats in pure burn and burn+ LA groups. At PIH 72.5, more P2X(4) receptor positive cells were observed in rats in pure burn group than in the other 4 groups (with P values below 0.05), and more P2X(4) receptor positive cells were observed in rats in burn+ LA group than in healthy+ normal saline, sham injury+ normal saline, and healthy+ LA groups (with P values below 0.05). (5) At PIH 72.5, the serum content of TNF-α and IL-1β of rats in pure burn group was significantly higher than that in the other 4 groups (with P values below 0.001). The serum content of TNF-α and IL-1β of rats in burn+ LA group was significantly lower than that in healthy+ normal saline, sham injury+ normal saline, and healthy+ LA groups (with P values below 0.001). Conclusions: LA has significant analgesic effects on severely burned rats, and it can ameliorate the excessive inflammational situation. The mechanism may be related to its inhibition of expression of P2X(4) receptor in microglias in the dorsal horn of spinal cord and reduction in the release of inflammatory factors TNF-α and IL-1β.

Active gratings tuned by thermoplasmonics-induced phase transition in vanadium dioxide thin films

We propose and investigate an active grating of gold metallic structure on vanadium dioxide (VO₂) thin film illuminated by an intense light. Nonuniform phase transition in VO₂ film is expected due to the thermoplasmonics effect where the plasmonic-induced light absorption features an enhanced local heat generation at nanometer-scale. The spatial profiles of the electric field, the heat generation, and the temperature distribution, as well as the temperature-dependent dielectric parameters in VO₂ film, are solved numerically in a self-consistent manner. Our results show that the evolution of the metallic and semiconducting phases of VO₂ changes the effective dielectric environment of the grating and modifies its optical response in a controlled way. The interplay of the thermoplasmonics effect and the phase transition processes can thus provide another degree of freedom in designing optical modulators or switches which are remotely tunable via incident light.

[Determination of hippuric acid and methylhippuric acid in urine by high performance liquid chromatography after extracted with acetonitrile]

OBJECTIVE

To establish pretreatment conditions of hippuric acid (HA)and methyl-hippuric acid (MHA)in urine and HPLC conditions.

METHODS

HA and MHA in urine were extracted with acetonitrile under acid condition and determinated by HPLC-DAD. The operating conditions by HPLC were C18 column (150 mm× 4.6 mm, 5 μm), methanol-0.2% acetic acid (contained 6.5 mmol/L potassium dihydrogen phosphate)(25∶75, V/V) as mobile phase,1 ml/min as flow rate and wavelength was at 254 nm.

RESULTS

The standard curves for HA, 2-MHA and 3-MHA(4-MHA)showed good linearity between 9.91~2 974.20 μg/ml(r=0.999 98), 1.91~573.60 μg/ml (r=0.999 84)and 2.00~598.65 μg/ml (r=0.999 85), respectively. The mean recoveries were 96.38%~98.01%, 83.17%~94.05 %, 103.22%~104.45%, respectively. The within-run precision were 0.50%~1.20%, 0.51%~1.59%, 0.49%~0.95%, respectively, and the between-run precision were 1.70%~3.20%, 1.30%~2.67%, 0.86%~2.74%, respectively. The detection limit of HA, 2-MHA and 3-MHA(4-MHA)were 0.18 μg/ml, 0.46 μg/ml and 0.12 μg/ml, and the low determination concentrations of the method were 0.36 μg/ml, 0.92 μg/ml and 0.24 μg/ml(1 ml urine). The urine can be kept 15 days at 4 ℃ refrigerator without significantly loss.

CONCLUSION

This method with simply pretreatment conforms to the relevant requirements of guide for establishing occupational health standards-part 5: determination methods of chemicals in biological materials. It can be used to detect HA and MHA in urine for occupational population exposure to toluene and xylene.

Dose effects of caffeine ingestion on acute hormonal responses to resistance exercise

AIM

The purpose of this study was to examine the dose effects of caffeine on acute hormonal responses to resistance exercise (RE).

METHODS

Twelve university males who regularly performed RE participated in this study. Subjects performed one repetition maximum (1RM) test and four treatments in a counterbalanced order: high dose (HD, 6 mg.kg(-1)), medium dose (MD, 4 mg.kg(-1)), low dose (LD, 2 mg.kg(-1)), and placebo (PLA). Subjects ingested caffeine 1 hour before RE and then performed RE (2 exercises, 3 sets of 10 repetitions at 75% of 1RM). Blood samples were collected before caffeine intake (pre-60), immediately before RE (pre-exe), and 0, 15, 30 min post RE (P0, P15, and P30, respectively) for analysis of serum testosterone, cortisol, insulin, glucose, lactate, and free fatty acid (FFA). Each experiment was separated by 7 days. Statistical analysis of two-way analysis of variance with repeated measures was applied. Statistical significance was set at α=0.05.

RESULTS

The concentrations of FFA (pre-exe) were significantly elevated following the HD, MD, and LD ingestions of caffeine. The concentrations of testosterone (P0, P15, and P30) and cortisol (pre-exe, P0, P15, and P30) at HD were significantly increased. However, the responses of insulin (P0 and P15) at HD and MD were significantly decreased.

CONCLUSION

The results of this study indicate that high doses of caffeine increase the responses of testosterone and cortisol. Moreover, moderate and high doses of caffeine attenuate the insulin responses.

Joint effects between urinary selenium and polymorphisms in methylation related genes on breast cancer risk

The aim of this study was to explore the associations of urinary selenium and polymorphisms in methylation related genes with breast cancer risk and the interactions on the risk. The present study involved in 240 female patients with incident breast cancer and 246 age-matched controls in two affiliated hospitals of Sun Yat-sen University in Guangzhou, China, from October 2009 to July 2010. DNMT1 rs2228611, MTHFR rs1801133, and MTR rs1805087 were genotyped using a matrix-assisted laser desorption/ionization time-of-flight mass spectrometry platform. Urinary concentration of selenium was measured by inductively coupled plasma mass spectrometry. Women with urinary selenium in the second tertile had a significant reduced breast cancer risk compared to those with urinary selenium in the lowest tertile [OR (95%CI): 0.50 (0.30, 0.81)]. DNMT1 rs2228611, MTHFR rs1801133, and MTR rs1805087 were not associated with breast cancer risk. Women with the third tertile of urinary selenium had a significant reduced breast cancer risk compared to those with the lowest tertile among women only with CC genotype [OR (95%CI): 0.55 (0.30, 1.00)] but not CT/TT genotypes [OR (95%CI): 1.58 (0.73, 3.42)] of MTHFR rs1801133 (P for interaction=0.044). Our results suggested that selenium was associated with a decreased risk of breast cancer and this beneficial effect was limited to women with CC genotype of MTHFR rs1801133.

Diet-quality scores and risk of hip fractures in elderly urban Chinese in Guangdong, China: a case-control study

This case-control study compared the associations of four widely used diet-quality scoring systems with the risk of hip fractures and assessed their utility in elderly Chinese. We found that individuals avoiding a low-quality diet have a lower risk of hip fractures in elderly Chinese.

INTRODUCTION

Few studies examined the associations of diet-quality scores on bone health, and no studies were available in Asians and compared their validity and utility in a study. We assessed the associations and utility of four widely used diet-quality scoring systems with the risk of hip fractures.

METHODS

A case-control study of 726 patients with hip fractures (diagnosed within 2 weeks) aged 55-80 years and 726 age- (within 3 years) and gender-matched controls was conducted in Guangdong, China (2009-2013). Dietary intake was assessed using a 79-item food frequency questionnaire with face-to-face interviews, and the Healthy Eating Index-2005 (HEI-2005, 12 items), the alternate Healthy Eating Index (aHEI, 8 items), the Diet Quality Index-International (DQI-I, 17 items), and the alternate Mediterranean Diet Score (aMed, 9 items) (the simplest one) were calculated.

RESULTS

All greater values of the diet-quality scores were significantly associated with a similar decreased risk of hip fractures (all p trends <0.001). The multivariate-adjusted odds ratios (ORs) and 95% confidential intervals (95% CIs) comparing the extreme groups of diet-quality scores were 0.29 (0.18, 0.46) (HEI-2005), 0.20 (0.12, 0.33) (aHEI), 0.25 (0.16, 0.39) (DQI-I), and 0.28 (0.18, 0.43) (aMed) in total subjects; and the corresponding ORs ranged from 0.04 to 0.27 for men and from 0.26 to 0.44 for women (all p trends <0.05), respectively.

CONCLUSIONS

Avoiding a low-quality diet is associated with a lower risk of hip fractures, and the aMed score is the best scoring system due to its equivalent performance and simplicity for the user.

Current noise in three-terminal hybrid quantum point contacts

We investigate the current noise of three-terminal hybrid structures at arbitrary bias voltages. Our results indicate that the noise can be a useful tool to extract dynamical information in multi-terminal hybrid structures. The zero-frequency noise is sensitive to the coupling with a normal lead. As a result, the characteristic multiple-step structure of the noise Fano factor due to multiple Andreev reflection will be suppressed as we increase this coupling. In addition, the internal dynamics due to processes of Andreev reflection and multiple Andreev reflection raises rich features in the noise spectrum corresponding to the energy differences of various dynamical processes.

Two Epstein-Barr virus-related serologic antibody tests in nasopharyngeal carcinoma screening: results from the initial phase of a cluster randomized controlled trial in Southern China

A nasopharyngeal carcinoma (NPC) mass screening trial using a combination of immunoglobulin A antibodies to Epstein-Barr virus capsid antigen and nuclear antigen-1 by enzyme-linked immunosorbent assay in addition to indirect mirror examination in the nasopharynx and/or lymphatic palpation (IMLP) was conducted in southern China. Cantonese aged 30-59 years residing in 2 cities randomly selected by cluster sampling, Sihui and Zhongshan, were invited to participate in this screening from May 2008 through May 2010. Participants were offered fiberoptic endoscopy examination and/or pathologic biopsy if their serologic tests reached our predefined level of high risk or if results from the physical examination indicated possible cancer (i.e., were IMLP positive). A total of 28,688 individuals were voluntarily screened in the initial round. The overall NPC detection rate was 0.14% (41/28,688) with an early diagnosis rate of 68.3% (28/41) during the first year of follow-up. Thirty-eight of 41 cases (92.7%) were detected among the high-risk group, and 7 of 41 cases (17.1%) were detected among the IMLP-positive group. The 2 Epstein-Barr virus serologic tests by enzyme-linked immunosorbent assay could be a feasible alternative for NPC screening in endemic areas. Further follow-up is needed to examine whether screening has an effect on decreasing mortality from NPC in these areas.

Disorder effect on the transport properties of graphene quantum well structures

We study the disorder effect on the transport properties of graphene quantum well structures using a phenomenological statistical model. By adopting the transfer matrix method combined with a Monte Carlo averaging procedure, we observe transitions from ballistic transport to the diffusive limit. It is found that the transmission probability of incident electrons is sensitive to the disorder effect. The significance of the disorder effect depends on the incident angle of the electrons. For normal incidence, the perfect transmission due to the Klein tunneling remains robust against the disorder effect. For tilted incidence, the transmission possibility can be suppressed. In particular, we found that the transmission probability for electrons with a very small angle, i.e. the wavevector along the transport direction is zero in the barrier, can be greatly suppressed. As a result, abrupt dips at these wavevectors emerge in the transmission spectrum.

Effect of substrate temperature on the in-situ formation of crystalline SiC nanostructured film using ultra-high-vacuum ion beam sputtering

In this paper, we have investigated the effect of substrate temperature on the in-situ formation of crystalline SiC (c-SiC) nanostructured film using ultra-high-vacuum ion beam sputtering (UHV IBS). The phase transformation, bonding behavior, morphology, composition and interdiffusion of the SiC nanostructured film were examined by X-ray diffraction, Raman spectra, high resolution scanning electron microscopy (SEM) with the attached energy dispersive X-ray detector and Auger electron spectroscopy (AES) depth profile, respectively. The in-situ formation of c-SiC was through interdiffusion and reaction between the sputtered carbon (C) and the crystalline Si (c-Si) substrate at high temperature. The amorphous-like C microstructure is stable up to 500 degrees C and transformed into a new phase of c-SiC together with the remained C at 600 degrees C. Complete C and Si reaction was found at 700 degrees C from Raman spectra without any C peaks. The main diving force for the c-SiC formation is the thermal energy to activate the large interdiffusion between C and c-Si which was detected from AES depth profile. Also, a nanoweb-like morphology of the c-SiC was observed on the surface of film from the SEM image. Therefore, the c-SiC nanostructured film can be obtained at 700 degrees C using in-situ UHV IBS process, which is much lower than conventional CVD c-SiC.

Phonon generation and phonon energy current fluctuation in quantum dot molecules

We study the phonon dynamics in a biased molecular junction with the interplay of electron-phonon coupling and Coulomb interaction. These interactions are taken into account within the self-consistent Born approximation and mean-field methods. It is found that the Coulomb interaction can enhance the nonequilibrium phonon generation. A general formula for the zero-frequency power spectral density of the phonon energy current fluctuation is presented in terms of the nonequilibrium phonon Green's functions.

QTL analysis of quality traits in an advanced backcross between Prunus persica cultivars and the wild relative species P. davidiana

Genetic control of the different attributes involved in peach quality has been investigated in an advanced backcross population derived from a cross between Prunus davidiana clone P1908, a wild parent with poor agronomic performance, and a commercial variety, Summergrand. A total of 24 physical and biochemical traits were investigated. Quantitative trait loci (QTLs) were detected for all the traits studied. We identified alleles from P. davidiana with agronomically favorable effects regarding fruit and stone sizes, sugar and acid concentrations and red flesh coloration, in clear contrast to its phenotype. We identified three main regions of the genome where alleles from P. davidiana had negative effects on multiple traits. In other regions, co-locations of QTLs with opposite effects on quality traits were also detected. We discuss the nature of these co-locations in the light of the probable physiological mechanisms involved. Strategies to cope with negative correlations between favorable traits and co-locations of P. davidiana alleles with negative effects on quality traits and positive effects regarding resistance to powdery mildew are discussed from a breeding point of view.

Modelling citrate metabolism in fruits: responses to growth and temperature

Citrate production and degradation during the last stage of fruit development were modelled by representing the fluxes through the enzymes of the citrate cycle and the malic enzyme, the transport of metabolites between the cytosol and the mitochondria, and the stoichiometry equations that relate these reactions. After solving the corresponding system of equations, the rate of citrate synthesis (or degradation) was expressed as a simple function of temperature, mesocarp weight, and respiration. The model was applied to peach fruit, and its parameters were estimated from the data of a 2-year field experiment. The predictions of the model were in agreement with experimental data. Simulations were made to analyse the responses to variations of temperature and fruit growth. Increasing fruit growth before stone hardening stimulated citrate production, while increasing fruit growth after stone hardening reduced it. Delaying the date at which the maximum growth rate was reached enhanced citrate production during most of the period. In the last weeks before harvest, increasing temperature depressed citrate production, while, at the beginning of the period studied, it enhanced it.

A study on the sectional anatomy of the oculomotor nerve and its related blood vessels with plastination and MRI

To obtain normal images and sectional anatomical data of the oculomotor nerve and its related arteries, the optimal angles and the length of intracisternal segment of the oculomotor nerve were measured on MPR images. Meanwhile, the relationships between the nerve and the basilar, posterior cerebral, superior cerebellar and posterior communicating arteries were observed from plastination slices, original images, MPR and MIP images. MRI revealed similar results to the plastination sections. The intracisternal segment of oculomotor nerve formed an angle with the posterior plane of the brainstem. The angle was significantly smaller in individuals under 10 and over 50 years old ( P<0.05), and there was no marked difference in the angle between the oculomotor nerve and the median sagittal plane among the different groups ( P>0.05). Shift of the basilar artery was more likely to be found in aged individuals. Most of the posterior cerebral and superior cerebellar arteries were close to the nerve, and a few of them seemed to compress it; for the posterior communicating artery, only the embryonic type was close to or seemed to compress the nerve. MRI is an accurate imaging technique for determination of the relationship of the oculomotor nerve to its related arteries.

[The polypeptides of mumps virus and their synthesis in infected chick embryo cells]

Strain ME of mumps grown in chick amniotic cavity and purified by differential centrifugation combined with sucrose gradient centrifugation. The structural polypeptides of purified virion were analyzed by SDS polyacrylamide gel electrophoresis. Eleven polypeptides were found. Their molecular weight were between 35K-72K dalton. In addition polymers of HN protein and F1 the large subunit of F protein were detected. Hela, Vero and CE cells were infected with ME strain of mumps virus. The CE cell reveals the most sensitive host cell. CE cell infected with mumps virus and labeled with [35S]-Met, SDS-PAGE and examined by autoradiography. It was found at least eight polypeptides were synthesis in host cells and their molecular weight were between 26.5K to 94K dalton. The time course of the synthesis of polypeptides in the cells were studies. Palse-Chase experiments demonstrated the posttranslational process of Fo----F.