Latissimus dorsi myocutaneous flap repair is effective after neoadjuvant chemotherapy for locally advanced breast cancer.

OBJECTIVE: To describe the clinical outcome and physical condition of patients with locally advanced breast cancer (LABC) who received neoadjuvant chemotherapy followed by mastectomy and latissimus dorsi myocutaneous flap repair. METHODS: A retrospective review of 142 patients with locally advanced breast cancer was selected from 1156 breast cancer patients in the South and North areas of The Affiliated Calmette Hospital of Kunming Medical University between May 2008 and December 2018. RESULTS: All participants (n = 142) were women aged 40-55 years (average age 47.35 ± 0.43 years) who received neoadjuvant chemotherapy followed by mastectomy and latissimus dorsi flap repair. The median follow-up period was 16 months (range 12-24 months). For stage of disease, there were 19 cases (13%) in stage IIB, 31 cases (22%) in stage IIIA, 39 cases (28%) in stage IIIB, and 53 cases (37%) in stage IIIC, which were statistically significant with the physical condition of patients (≤ 0.001). Neoadjuvant chemotherapy was administered to shrink the tumors, and an average tumor size decrease from 10.05 ± 1.59 cm × (8.07 ± 1.54) cm to 6.11 ± 1.72 cm × (3.91 ± 1.52) cm (P < 0.001) was considered statistically significant. A t test was used for the ECOG score statistics, and the results showed that the scores were statistically significant (≤ 0.001) before and after neoadjuvant chemotherapy and after surgery. CONCLUSIONS: Neoadjuvant chemotherapy is an accepted treatment option for patients with locally advanced breast cancer, and the use of a latissimus dorsi musculocutaneous flap for post-mastectomy reconstruction may improve the patients' physical condition. Our results indicated that this strategy was safe and feasible.

Effect of TiC Content on Microstructure and Wear Performance of 17-4PH Stainless Steel Composites Manufactured by Indirect Metal 3D Printing.

In order to improve the performance of 17-4PH under wear conditions (e.g., gears, etc.) and reduce the cost of metal additive manufacturing, TiC needs to be added to 17-4PH to improve its wear resistance. Micron-sized TiC-reinforced 17-4PH stainless steel composites with different contents (0-15 wt%) have been prepared by fused filament fabrication 3D printing for the first time. The effects of TiC content on the structure and properties of composites were studied by XRD, SEM, and sliding wear. The obtained results show that the microstructure of TiC-reinforced 17-4PH stainless steel composites mainly consists of austenite. With the increase in TiC content, the grain size is obviously refined, and the average grain size decreases from 65.58 µm to 19.41 µm. The relative densities of the composites are maintained above 95% with the addition of TiC. The interfaces between TiC particles and the 17-4PH matrix are metallurgical bonds. The hardness of the composites increases and then decreases with increasing TiC content, and the maximum hardness (434 HV) is obtained after adding 10 wt.% of TiC content. The wear rate of the composites was reduced from 2.191 × 10-5 mm3 /(N‧m) to 0.509 × 10-5 mm3 /(N‧m), which is a 3.3-fold increase in wear resistance. The COF value declines with the addition of TiC. The reasons for the significant improvement in the composites' performance are fine grain strengthening, solid solution strengthening, and second phase strengthening. The wear mechanisms are mainly abrasive and adhesive wear. Compared to the 10 wt% TiC composites, the 15 wt% TiC composites show limited improvement in wear resistance due to more microcracks and TiC agglomeration.

[Roles of mitochondrial DNA somatic mutations in the pathogenesis of benign breast disease: a perspective from whole genome study].

OBJECTIVE: To explore the potential roles of mitochondrial DNA somatic mutations in benign breast disease based on the entire genome of mitochondrial DNA and elucidate the relationship between benign breast disease and breast cancer. METHODS: The genomic DNA of tumor tissue and peripheral blood in 28 benign breast disease patients with an average age of 33 years (range: 30 - 50) were extracted respectively. According to the revised Cambridge reference sequence and phylogenetic tree reconstruction, the mutations were identified and distinction was made between somatic mutations and private mitochondrial DNA mutations by haplogroup. RESULTS: Seven somatic mutations were detected. One mutation was located in the control region whereas the other six lied in the coding region. Further analyses revealed that, out of these 6 coding-region mutations, 4 were non-synonymous and would introduce the changes of amino acids. CONCLUSION: The mutations of mitochondrial DNA may play potential roles in the occurrence and development of benign breast disease.

[Transcriptome analysis on responses of leaf photosynthesis and nitrogen metabolism of Larix gmelinii to environmental change]. / å ´å®‰è½å¶æ¾å¶å ‰åˆä¸Žæ°®ä»£è°¢å¯¹çŽ¯å¢ƒå˜åŒ–å“åº”çš„è½¬å½•ç»„åˆ†æž.

To reveal molecular mechanisms underlying photosynthesis responses of Dahurian larch (Larix gmelinii) to environmental changes, we used the high-throughput sequencing technology to sequence the transcriptome of larch leaves from four latitudinal sites with different environmental conditions, and compared differential expression genes (DEGs). The four sites from high- to low-latitude were Tahe (52°52' N), Songling (50°72' N), Heihe (49°22' N), and Dailing (47°08' N). A total of 282428811 clean reads were sequenced out, among which the abundace of DEGs were 16915, 18812, 28536, 20635, 29957 and 23617 for the Tahe-Songling, Tahe-Heihe, Tahe-Dailing, Songling-Heihe, Songling-Dailing, and Heihe-Dailing comparisons, respectively. The expression of nine Psb genes family (i.e., PsbB, PsbK, PsbO, PsbP, PsbQ, PsbS, PsbW, Psb27, and Psb28) encoding Photosystem Ⅱ and that of three genes (ATPF1A,atpA, ATPF1G, atpG, and ATPF1D, atpH) encoding F-type ATPase, which were involved in photosynthesis pathway, were significantly up-regulated with increasing environmental differences among the sites. A similar up-regulation pattern occurred for the expression of genes encoding glutamine synthetase (glnA, GLUL), nitrate reductase (NR), and carbonic anhydrase (cynT, can) that were involved in nitrogen metabolism pathway. The numbers of DEGs and up-regulated genes increased with the increases in environmental changes among the sites, resulting in inter-site divergence of photosynthetic capacity of larch trees.

Fluid mechanical dispersion of airborne pollutants inside urban street canyons subjecting to multi-component ventilation and unstable thermal stratifications.

The pedestrian level pollutant transport in street canyons with multiple aspect ratios (H/W) is numerically investigated in the present work, regarding of various unstable thermal stratification scenarios and plain surrounding. Non-isothermal turbulent wind flow, temperature field and pollutant spread within and above the street canyons are solved by the realizable k-ε turbulence model along with the enhanced wall treatment. One-vortex flow regime is observed for shallow canyons with H/W=0.5, whereas multi-vortex flow regime is observed for deep canyons with H/W=2.0. Both one-vortex and multi-vortex regimes could be observed for the street canyons with H/W=1.0, where the secondary vortex could be initiated by the flow separation and intensified by unstable thermal stratification. Air exchange rate (AER) and pollutant retention time are adopted to respectively evaluate the street canyon ventilation and pollutant removal performance. A second-order polynomial functional relationship is established between AER and Richardson number (Ri). Similar functional relationship could be established between retention time and Ri, and it is only valid for canyons with one-vortex flow regime. In addition, retention time could be prolonged abruptly for canyons with multi-vortex flow regime. Very weak secondary vortex is presented at the ground level of deep canyons with mild stratification, where pollutants are highly accumulated. However, with the decrease of Ri, pollutant concentration adjacent to the ground reduces accordingly. Present research could be applied to guide the urban design and city planning for enhancing pedestrian environment.