Recurrent SARS-CoV-2 RNA positivity and prolonged viral shedding in a patient with COVID-19: a case report.

BACKGROUND: The ongoing coronavirus disease 2019 (COVID-19) global pandemic caused by the SARS-CoV-2 virus remains a major threat to public health. At present, it is recommended that patients with known or suspected COVID-19 undergo quarantine or medical observation for 14 days. However, recurrent SARS-CoV-2 RNA positivity and prolonged viral shedding have been documented in convalescent COVID-19 patients, complicating efforts to control viral spread and ensure patient recovery. CASE PRESENTATION: We report the case of a patient who experienced two recurrent episodes of SARS-CoV-2 RNA and IgM positivity and viral shedding over 60 days during hospitalization. CONCLUSIONS: This case report demonstrates that relapses of SARS-CoV-2 RNA and IgM positivity may occur even after COVID-19 symptoms have resolved, possibly as a consequence of prolonged viral shedding rather than re-infection.

[Research of influence factors on spectral recognition for cotton leaf infected by Verticillium wilt].

Through carrying out spectral test experiment, the influence factors of spectrum test were analyzed, the influence degree of various factors in spectral recognition was explicated and the method of spectra test was optimized for cotton leaf infected by verticillium wilt. The results indicated that under different severity levels, the shape and value of reflectance of disease symptoms part were Significantly higher than healthy part on cotton leaf, compared with the black board as baseboard, the spectral values of disease leaves were slightly higher in visible light wavebands and significantly higher in others wavebands than healthy leaves on white baseboard. Different position of leaf on cotton plant has different effect degree to the recognition of disease, the effect of stem leaf was more obvious than that of else leaf, the identical leaf position was less influenced by disease than band. Test time and cotton varieties had less influence on recognizing disease by spectra, and the effect of the same condition was acceptable. Test site had no effect on disease recognition by spectra. The effect of each factor was different for recognizing disease leaf by spectra, and this study will provide reference for the researchers of crop disease diagnosis by spectra.

[Estimated nitrogen nutrition index based on the hyperspectral for wheat of drip irrigation under mulch].

The accurate wheat management needs a reasonable nitrogen application, and it is one of the key measures for real-time and quantitatively monitoring of nitrogen status to gain the higher yield of wheat. In the present study, two field experiments were conducted with different nitrogen stress and wheat cultivars, the relationship was analyzed between spectral parameters and the partial factor productivity from applied N (PFPn), and the estimating model was established for PFP, in the growth stages of wheat. The result indicated that there was a highly significant correlation between the PFP, and GreenNDVI at jointing, the correlation coefficient (r) was 0.6404, the estimating model of PFPn was established, and the root mean square errors (RMSE) was 0.4597. The result indicated that the PFPn can be effectively estimated by using spectral parameters.

[Application of latissimus dorsi muscle flap for breast conservation in breast cancer].

OBJECTIVE: Breast conserving surgery (BCS) is one of standard treatment approaches in early breast cancer. Although most defect after BCS can be repaired, the cosmetic outcomes are unsatisfactory in the patients with poor tumor/breast ratio. Oncoplastic surgery (OPS) has emerged as a new approach for providing adequate tumor resection without compromise of aesthetic outcomes in BCS. Our purpose is to explore the cosmetic outcomes of applying latissimus dorsi (LD) muscle flap to reshape severe breast conservation deformities in breast cancer. METHODS: Totally 24 cases of breast cancer were studied. The tumor size was 3.0 - 5.5 cm (median 3.5 cm). All the cases underwent BCS and achieved negative margin by frozen sections examination. Then LD flap reshaping were performed. All the patients received whole breast radiotherapy ± chemotherapy ± endocrine therapy. RESULTS: All the LD flaps were alive without skin necrosis. After a median 23-month follow-up, all the cases were disease-free surviving. The whole breast radiotherapy had no significant effect on the LD flaps. The rate of good cosmetic results was 79.2%. The subjective satisfactory rate of the patients was 96%. CONCLUSIONS: Both satisfactory aesthetic outcome and good treatment effect were obtained using LD flap to reshape severe breast conservation deformity. OPS offers tools for breast conservation in patients otherwise destined for mastectomy or poor aesthetic outcome, such as large tumor/breast ratio, nipple-areola complex tumor, ductal carcinoma in situ, neoadjuvant chemotherapy cases and so on.

[Study on hyperspectral estimation of pigment contents in leaves of cotton under disease stress].

The spectrum reflectance and pigment contents of cotton leaves infected with Verticillium wilt were measured in cotton disease nursery and field in different growth phases, and severity level of Verticillium wilt was investigated. The correlation between pigment contents of cotton leaves with Verticillium wilt and spectra reflectance, the first derivative of reflectance and spectral characteristic parameters were analyzed respectively. The estimation models about leaves pigment contents of disease cotton were established and tested. The results indicated that the correlations were best significant between chlorophyll a, b and a+b contents of leaves and spectral reflectance in visible wave bands, the first derivative spectrum at the wavelength regions of blue edge, yellow edge and red edge, and all spectral characteristic parameters (excluding red edge swing Dr). The models of transformed chlorophyll absorption in reflectance index (TCAR) and the new model of normalized difference vegetation index (NDVI [702,758]) had best estimated precision, and the relative errors were in average within 1.3%. Given that the model of NDVI [702,758] is very simple and practical, it was commended as a best model to estimate chlorophyll a, b and a+b contents of disease cotton. This study shows that leaves hyperspectra data can be used to estimate the pigment contents of cotton leaves quantitatively. This conclusion has also great practice and application value for monitoring the growth state and disease influence evaluation on cotton by using hyperspectral remote sensing.

[Monitoring canopy nitrogen status in winter wheat of growth anaphase with hyperspectral remote sensing].

Biomass, leaf area index (LAI) and nitrogen status are important parameters for indicating crop growth potential and photosynthetic productivity in wheat. Nondestructive, quick assessment of leaf dry weight, LAI and nitrogen content is necessary for nitrogen nutrition diagnosis and cultural regulation in wheat production. In order to establish the monitoring model of nitrogen richness in winter wheat of growth anaphase, studying the relationship between the nitrogen richness (NR) containing nitrogen density, LAI and leaf dry weight and the difference of hyperspectral reflectance rates (deltaR), we conducted a comparable experiment with five winter wheat varieties under nitrogen application level of 0, 100, 200 and 400 kg x N x ha(-1). The results indicated the NRs of the different varieties of winter wheat leaves increased with increasing growth stage while in the different nitrogen levels it was sequenced as: NO>N3>N1>N2. Twelve vegetation indices were compared with corresponding NR. The NR had significantly negative correlation to TCARI and VD672 in those vegetation indices, and their correlations (r) arrived at 0.870 and 0.855, respectively. The coefficients of determination (R2) of two models were 0.757 and 0.731 by erecting model with the two indexes and NR Root mean square error (RMSE), relative error (RE) and determination coefficient between measured and estimated NR were employed to test the model reliability and predicting accuracy. Accuracy rates of the models based on TCARI and VD672 achieved 84.56% and 80.13%. The overall results suggested that leaf nitrogen status of growth anaphase in winter wheat has stable relationships with some vegetation indexes, especially index of TCARI and VD672.

[Research on the postoperative complications and its risk factors of breast reconstruction with abdominal flaps].

OBJECTIVE: To study the postoperative complications and its risk factors in patients underwent breast reconstruction with abdominal flaps. METHODS: The clinical data of 115 cases underwent breast reconstructions with abdominal flaps from May 2001 to October 2008 was reviewed. The postoperative complications included total flap necrosis, partial flap necrosis, fat necrosis, hernia, bulge, fat liquefaction and infection. The risk factors of complication rates were also evaluated. RESULTS: The total postoperative complications rate was 17.4% (20/115). No severe complications was found, such as total flap necrosis, hernia and bulge. The most common complications of flap was fat necrosis which occurred in 6 cases (5.2%), partial flap necrosis in 5 cases (4.3%) and infection in 1 case (0.9%). The donor-site complications included fat liquefaction which occurred in 8 cases (7.0%) and infection in 3 cases (2.6%). No significant relation was found between patient's age, body mass index (BMI), timing of surgery and the postoperative complication rate. The postoperative complications occurred more frequently in active smokers, patients with radiotherapy history, or reconstructions with pedicled transverse rectus abdominis myocutaneous (TRAM) flaps. But no significant difference was found in those factors. CONCLUSIONS: Fewer complications happens in patients with a reconstruction with deep inferior epigastric perforator (DIEP) flap. Abdominal flap should be performed with more consideration in active smokers or patients with a radiotherapy history. Age and obesity should not be contraindications to breast reconstruction with abdominal flaps.

[Screening of differential expression genes between primary breast cancer and its lymph node metastasis using single primer amplification of cDNA for microarray].

OBJECTIVE: To screen genes related to breast cancer metastasis by comparing difference of expression profile between primary breast cancer and its lymph node metastasis. METHODS: The cell total RNA was extracted from 10 breast cancer specimens, including the primary cancer and metastatic cancer tissues of axillary lymph nodes resected during operation. Single primer amplification (SPA) was used to prepare fluorescence-labeled targets and then Oligo microarray concluding 21 000 human functional genes was used to screen out 1.5 fold or more differential expression genes in at least 5 pairs of samples. The screened-out genes were identified by real-time PCR. RESULTS: Preparing targets by using SPA reduced the initial RNA to 0.25 microg, with 57 genes screened out, the expression of 19 of which were up-regulated and the expression of 38 of which were down-regulated in the metastatic tissues. Eight differentially expressed genes were related to cell migration and adhesion, 14 to signal transduction, and 14 to cell growth or metabolism. Real-time PCR showed that the fibronectin (FN) mRNA expression in the lymph node metastasis was only 1/3.6 of that in the matched primary breast cancer in 30 cases (t = -3.188, P = 0.003). CONCLUSION: SPA is a sensitive method for preparing targets. Genes related to cell migration and adhesion, signal transduction, and cell growth or metabolism, which are associated with the biology process of metastasis have been screened out. FN as a potent marker may contribute to diagnosis of metastasis and prognosis for breast cancer patients.

[Clinical significance and relationship of expression of matrix metalloproteinase-2 mRNA with breast cancer metastasis].

OBJECTIVE: To discuss the clinical significance of matrix metalloproteinase-2 (MMP-2) mRNA and the relationship of MMP-2 mRNA expression with breast cancer metastasis. METHOD: Detect MMP-2 mRNA expression of 30 breast cancer, metastatic lymphnode and 116 clinical breast cancer samples by flurence-quantitative RT-PCR and analysis the relativity of MMP-2 mRNA expression with clinical, pathology factors. RESULTS: MMP-2 mRNA expression in 30 metastatic lymphnode is lower than in primary breast cancer (t = -3.293, P < 0.05). The mRNA expression of MMP-2 in tumor > 2 cm is lower than in tumor

Estimation of wheat agronomic parameters using new spectral indices.

Crop agronomic parameters (leaf area index (LAI), nitrogen (N) uptake, total chlorophyll (Chl) content ) are very important for the prediction of crop growth. The objective of this experiment was to investigate whether the wheat LAI, N uptake, and total Chl content could be accurately predicted using spectral indices collected at different stages of wheat growth. Firstly, the product of the optimized soil-adjusted vegetation index and wheat biomass dry weight (OSAVI×BDW) were used to estimate LAI, N uptake, and total Chl content; secondly, BDW was replaced by spectral indices to establish new spectral indices (OSAVI×OSAVI, OSAVI×SIPI, OSAVI×CIred edge, OSAVI×CIgreen mode and OSAVI×EVI2); finally, we used the new spectral indices for estimating LAI, N uptake, and total Chl content. The results showed that the new spectral indices could be used to accurately estimate LAI, N uptake, and total Chl content. The highest R(2) and the lowest RMSEs were 0.711 and 0.78 (OSAVI×EVI2), 0.785 and 3.98 g/m(2) (OSAVI×CIred edge) and 0.846 and 0.65 g/m(2) (OSAVI×CIred edge) for LAI, nitrogen uptake and total Chl content, respectively. The new spectral indices performed better than the OSAVI alone, and the problems of a lack of sensitivity at earlier growth stages and saturation at later growth stages, which are typically associated with the OSAVI, were improved. The overall results indicated that this new spectral indices provided the best approximation for the estimation of agronomic indices for all growth stages of wheat.

NEFL mRNA expression level is a prognostic factor for early-stage breast cancer patients.

Neurofilament, light polypeptide (NEFL) was demonstrated to be ectopically expressed in breast cancer tissues and decreased in lymph node metastases compared to the paired primary breast cancers in our previous study. Moreover, in several studies, NEFL was regarded as a tumor suppressor gene, and its loss of heterozygosity (LOH) was related to carcinogenesis and metastasis in several types of cancer. To explore the role of NEFL in the progression of breast cancer and to evaluate its clinical significance, we detected the NEFL mRNA level in normal breast tissues, primary breast cancer samples and lymph node metastases, and then analyzed the association between the NEFL expression level and several clinicopathological parameters and disease-free survival (DFS). NEFL mRNA was found to be expressed in 92.3% of breast malignancies and down-regulated in lymph node metastases compared to the paired primary tumors. NEFL mRNA level was lower in primary breast cancers with positive lymph nodes than in cancers with negative lymph nodes. Moreover, a low expression level of NEFL mRNA indicated a poor five-year DFS for early-stage breast cancer patients. Thus, NEFL mRNA is ectopically expressed in breast malignancies and could be a potential prognostic factor for early-stage breast cancer patients.

[Application of latissimus dorsi-myocutaneous flap in breast reconstruction].

OBJECTIVE: To investigate the design, procedures and effect of latissimus dorsi-myocutaneous flap (LDMF) for breast reconstruction. METHODS: From May, 2005 to April, 2006, 18 consecutive patients underwent breast reconstruction with LDMF. Combined breast implants were also inserted in 8 of the 18 cases. The procedure duration, complication and aesthetic results were assessed. RESULTS: The mean procedure duration was 147 minutes. There was no flap loss and no severe complications. The reconstructed breast was a little over high in one patient. All the other 17 patients (94.4%) were very satisfied with the aesthetic result. CONCLUSIONS: LDMF or a combination of LDMF with breast implants is a reliable method for breast reconstruction with low complication. The procedure is easily performed with good aesthetic result.