Stability analysis and Hopf bifurcation of a fractional order mathematical model with time delay for nutrient-phytoplankton-zooplankton.

In recent years, some researchers paid their attention to the interaction between toxic phytoplankton and zooplankton. Their studies showed that the mechanism of food selection in zooplankton is still immature and when different algae of the same species (toxic and nontoxic) coexist, some zooplankton may not be able to distinguish between toxic and nontoxic algae, and even show a slight preference for toxic strains. Thus, in this article, a fractional order mathematical model with time delay is constructed to describe the interaction of nutrient-phytoplankton-toxic phytoplankton-zooplankton. The main purpose of this paper is to study the influence of fractional order and time delay on the ecosystem. The sufficient conditions for the existence and local stability of each equilibrium are obtained by using fractional order stability theory. By choosing time delay as the bifurcation parameter, we find that Hopf bifurcation occurs when the time delay passes through a sequence of critical values. After that, some numerical simulations are performed to support the analytic results. At last we make some conclusion and point out some possible future work.

Multiple-bar Nuss operation: an individualized treatment scheme for patients with significantly asymmetric pectus excavatum.

BACKGROUND: Research into multiple-bar Nuss operations for the treatment of wide-range or significantly asymmetric pectus excavatum is rarely reported. This paper aims to explore the curative effects of multiple-bar Nuss operations on wide-range or significantly asymmetric pectus excavatum. METHODS: We reviewed the clinical data of 153 patients with pectus excavatum who were treated in our hospital from September 2006 to August 2014. All the patients had wide-range or significantly asymmetric pectus excavatum and underwent multiple-bar Nuss operations performed by the author. RESULTS: All 153 patients agreed to undergo the operation. The median age was 17 y (10.2-41 y). The median Haller index was 3.98 (3.2-25). One hundred and fifty-one patients accepted treatment with two bars, and 2 cases accepted treatment with three bars. The median operation time was 123 min (65-500 min), the median blood loss was 20 mL (2-200 mL), and the median postoperative hospital stay was 6 days (3-33 days). The incidence rates of pleural effusion, pneumothorax and hydropneumothorax that required drainage treatment were 0.7% (1/153), 1.3% (2/153) and 3.3% (5/153), respectively. Displacement of a bar occurred in one case, and bar exposure occurred in 7 cases. Therefore, 2 cases had the bars removed early, within 2 years postoperation. One patient with severe depression (Haller index: 8.8) had an unhealed auxiliary incision of the xiphoid process, and although the incision was cured after the early removal of the inferior bar, the deformity recurred. There were no cases of death. Currently, 51.6% (79/153) of the cases have had the bars removed. The most recent follow-up revealed that patients' median satisfaction score for the surgical correction effect was 9 points (10 points indicated full satisfaction). CONCLUSIONS: For patients with significantly asymmetric and severely deformed pectus excavatum, the multiple-bar Nuss operation not only is safe and effective but can also achieve a better cosmetic appearance. However, we should continue to explore technical improvements.

TCF19 contributes to cell proliferation of non-small cell lung cancer by inhibiting FOXO1.

Transcription factor 19 (TCF19) harbors a forkhead association (FHA) domain, a proline-rich region, a PHD or RING finger region, suggesting that TCF19 possesses a powerful function. However, its expression and function remains unknown in non-small-cell lung cancer (NSCLC). The function cluster analysis was carried out using Metascape website. 3-(4,5-Dimethyl-2-thiazolyl)2,5-diphenyl-2H-tetrazolium bromide (MTT), colony formation, and anchorage-independent growth ability assay were carried out to detect the effect of TCF19 on cell proliferation. Bromodeoxyuridine (Brdu) labeling and flow cytometry assay were used to evaluate the effect of TCF19 on cell-cycle progression. Quantitative polymerase chain reaction and chromatin immunoprecipitation assay were performed to investigate the mechanism by which TCF19 is involved in cell-cycle transition. By analyzing the publicly available dataset, The Cancer Genome Atlas (TCGA), we found that TCF19 is significantly increased in the lung adenocarcinoma (LAC) and squamous cell carcinoma (SCC), two primary histological subtype of NSCLC. Besides, further function cluster analysis exhibited that TCF19 may mainly participate in cell cycle. MTT, colony formation, and anchorage-independent growth ability assay confirmed that overexpression of TCF19 enhances the proliferation of both LAC and SCC cells. Besides, further experiments revealed that TCF19 contributes to cell cycle G1/S transition. Not only that, upregulation of TCF19 can inhibit the expression of p21, p27, and p57, while promote the expression of cyclin D1 by inhibiting FOXO1. Our research offers important evidence that TCF19 can promote cell-cycle progression of NSCLC cells, and TCF19 may served as novel therapeutic targets.

Surgical correction of 639 pectus excavatum cases via the Nuss procedure.

BACKGROUND: To review the clinical experience and short- to middle-term effects of the Nuss procedure for correction of pectus excavatum (PE). METHODS: From September 2006 to August 2014, 639 patients with PE were treated using the Nuss procedure. Of these, 546 were male and 93 were female. The mean age was 15.3±5.8 years (2.5-49 years). Preoperative chest CT scans Haller index (HI) was 4.3±1.7 (2.9-17.4), with 75 cases of mild PE (HI <3.2), 114 cases of moderate PE (HI 3.2-3.5), 393 cases of severe PE (HI 3.6-6.0), and 57 cases of extremely severe PE (HI >6.0). RESULTS: A total of 638 patients successfully completed the surgery, an 11-year-old male patient who died after the surgery had undergone ventricular septal defect closure surgery through a sternal incision 7 years ago. The mean operative time was 64.3±41.7 min (40-310 min). Excluding the patient who died, the average blood loss was 24.5±17.8 mL (10-160 mL). The average length of postoperative hospital stay was 5.2±2.9 days (4-36 days). A total of 484 cases (75.7%) required 1 steel bar insertion, 153 cases (24.0%) required 2 steel bars, and 2 cases (0.3%) required 3 bars. Postoperative evaluation of the surgery outcomes revealed the following: excellent in 504 cases, good in 105, fair in 28 and poor in 2, good quality rate was 95.3%. CONCLUSIONS: Correction of PE via the Nuss procedure is minimally invasive and simple to perform with good short and mid-term effects, while long-term efficacy remains to be determined.