Effects of prebiotic supplement on gut microbiota, drug bioavailability, and adverse effects in patients with colorectal cancer at different primary tumor locations receiving chemotherapy: study protocol for a randomized clinical trial.

BACKGROUND: The prevalence of colorectal cancer (CRC) worldwide is a huge challenge to human health. Primary tumor locations found to impact prognosis and response to therapy. The important role of gut microbiota in the progression and treatment of CRC has led to many attempts of alleviating chemotherapy-induced adverse effects using microecologics. However, the underlying mechanism of the difference in the prognosis of different primary tumor locations and the synergistic effect of prebiotics on chemotherapy need to be further elucidated. This study aims to explore the differences in tumor microbiota and examine the effectiveness of xylooligosaccharides (XOS) on gut microbiota, adverse effects, and bioavailability of chemotherapy drugs in CRC patients at different primary tumor locations. METHODS: This is a double-blinded, randomized, parallel controlled clinical trial. Participants with left-sided CRC (LSCRC, n = 50) and right-sided CC (RSCC, n = 50) will randomly allocated to prebiotic group (n = 25) or control group (n = 25) and will receive either a daily XOS (3 g/day) or placebo, respectively, for 12 weeks. The primary outcomes will be the differences in the mucosa microbiota composition at different tumor locations and differences in gut microbiota composition, adverse effects, and blood concentration of capecitabine posttreatment. The secondary outcomes will include other blood indicators, short-chain fatty acids (SCFAs) concentration, quality of life, and mental health. DISCUSSION: This study will reveal the potential benefits of prebiotic for improving the gut microbiota composition, alleviating the adverse effects, and improving the efficacy of chemotherapy in patients with CRC. In addition, this study will provide data on the different distribution of tumor microbiota and the different changes of gut microbiota during treatment in LSCRC and RSCC, which may provide novel insights into personalized cancer treatment strategies based on primary tumor locations and gut microbiota in the future. TRIAL REGISTRATION: Chinese Clinical Trial Registry ( www.chictr.org.cn ): ChiCTR2100046237. Registered on 12 May 2021.

Functional Genetic Variants in SPHK1 Affect Susceptibility to Gastric Cancer in a Chinese Population.

BACKGROUND: An escalating number of studies have provided identified evidence that sphingosine kinase 1 (SPHK1) plays an essential role in carcinogenesis. This present study was devised to seek the possible correlation of two tag single-nucleotide polymorphisms (SNPs) in SPHK1 (rs3744037 T>C, rs346801 C>T) with the susceptibility to gastric cancer (GC). METHODS: This present case-control study was comprised of 710 patients with GC and 710 gender- and age-matched cancer-free individuals. The genotypes of the individuals were acquired by the TaqMan-MGB method. SPHK1 mRNA level was examined in 60 paired cancerous and noncancerous tissues using quantitative reverse transcription-polymerase chain reaction (qRT-PCR). RESULTS: Our results suggested that the variant genotype T allele of SPHK1 rs346801 increased the GC risk in the study population [CT vs. CC, odds ratio (OR) = 1.385, 95% confidence interval (CI) = 1.096 - 1.751; TT vs. CC, OR = 2.502, 95% CI = 1.078 - 5.806; CT+TT vs. CC, OR = 1.434, 95% CI = 1.140 - 1.804]. Furthermore, in stratified analyses, rs346801 variant genotypes were associated with a conspicuous risk of GC in younger individuals (< 62 years), females, non-smokers, and individuals from rural areas. In addition, the carriers with variant genotype CT, TT, and CT+TT were observed to possess the higher SPHK1 messenger RNA levels than those with CC genotype in GC specimens. CONCLUSIONS: These results strongly demonstrated that the SPHK1 rs346801 C>T polymorphism may contribute to the susceptibility to gastric cancer in Chinese population and affect the expression of SPHK1 and, therefore, may act as a novel biomarker for predicting gastric cancer.

Synthesis of Si/SiO2 core-shell nanowire arrays and broadband anti-reflection effects in diluted Si nanowire arrays by adjusting dielectric shell thickness.

A low filling ratio and enhanced absorption is needed to enable the full potential of Si nanowire (NW) arrays for optoelectronic applications. In this paper, we report a versatile, scalable fabrication technique that uses nanosphere lithography (NSL) patterning for the synthesis of vertically aligned Si and Si/SiO2 NW arrays. The optical reflection of the NW arrays can be substantially suppressed by the addition of the transparent shell. Meanwhile, by the finite-difference time-domain (FDTD) simulation, we find that the absorption enhancement in the core Si NW can be obtained by adding the transparent shell. The special absorption enhancement of the Si NW arrays with a core-shell structure can be theoretically understood by modal analysis. The absorption in such Si NW array structures is very sensitive to the thickness of transparent coating. By the addition of a SiO2 shell layer, the absorption in the inner Si NW array can be substantially enhanced. Furthermore, significant absorption enhancement and broadband anti-reflection effects can be achieved by the diluted Si NWs combined with the single dielectric shell.

On-Demand Fabrication of Si/SiO2 Nanowire Arrays by Nanosphere Lithography and Subsequent Thermal Oxidation.

We demonstrate the fabrication of the large-area arrays of vertically aligned Si/SiO2 nanowires with full tunability of the geometry of the single nanowires by the metal-assisted chemical etching technique and the following thermal oxidation process. To fabricate the geometry controllable Si/SiO2 nanowire (NW) arrays, two critical issues relating with the size control of polystyrene reduction and oxide thickness evolution are investigated. Through analyzing the morphology evolutions of polystyrene particles, we give a quantitative description on the diameter variations of polystyrene particles with the etching time of plasma etching. Based on this, pure Si NW arrays with controllable geometry are generated. Then the oxide dynamic of Si NW is analyzed by the extended Deal-Grove model. By control, the initial Si NWs and the thermal oxidation time, the well-aligned Si/SiO2 composite NW arrays with controllable geometry are obtained.

Ti/Au Cathode for Electronic transport material-free organic-inorganic hybrid perovskite solar cells.

We have fabricated organic-inorganic hybrid perovskite solar cell that uses a Ti/Au multilayer as cathode and does not use electron transport materials, and achieved the highest power conversion efficiency close to 13% with high reproducibility and hysteresis-free photocurrent curves. Our cell has a Schottky planar heterojunction structure (ITO/PEDOT:PSS/perovskite/Ti/Au), in which the Ti insertion layer isolate the perovskite and Au layers, thus proving good contact between the Au and perovskite and increasing the cells' shunt resistance greatly. Moreover, the Ti/Au cathode in direct contact with hybrid perovskite showed no reaction for a long-term exposure to the air, and can provide sufficient protection and avoid the perovskite and PEDOT:PSS layers contact with moisture. Hence, the Ti/Au based devices retain about 70% of their original efficiency after 300 h storage in the ambient environment.

Is early surveillance with CT scan necessary in patients with stage II/III colorectal cancer: a retrospective study.

BACKGROUND AND OBJECTIVES: This analysis aims to evaluate the value of early surveillance within 6 months after resection for stage II/III colorectal cancer (CRC). METHODS: Patients with stage II/III CRC who received surgery with curative intent for CRC were included. CT scans of the chest, abdomen, and pelvis performed within 6 months after surgery were evaluated. RESULTS: Among 150 patients included in the study, 10 patients (1 occurred in stage II disease and 9 occurred in stage III) were diagnosed as recurrence within 6 months after surgery. The proportion of patients diagnosed as recurrence was significantly higher in stage III disease than in stage II disease (P = 0.01). The likelihood of recurrence within 6 months was associated with the extent of lymph node metastases (r = 0.205, P = 0.012). Three patients with recurrent disease underwent salvage resection with curative intent. CONCLUSIONS: Early surveillance with CT scan within 6 months after curative resection may not be necessary for stage II disease. Although, the strategy may be helpful for stage III disease considering the high incidence of salvage surgery for recurrence disease, the early detection of recurrence could not be translated into survival benefit.