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We experimentally demonstrated a simple and effective method to write long period fiber gratings (LPFGs) with low fiber grating birefringence using high frequency CO2 laser pulses. Such LPFGs were fabricated by introducing twist strains to the fiber and then exposing the fiber to the laser. We theoretically analyzed the influence of the twist strains on the spectra of the LPFGs, and examined bend characteristics of twisted long period fiber gratings (T-LPFGs). Experimental results showed that T-LPFGs exhibited clear spectra, low insertion loss, and low polarization-dependent loss (PDL) compared with conventional LPFGs exposed to a single-side CO2 laser beam. The slope of the linear equation of the distance between the two split resonance peaks in the bending experiment is 20.55 nm/m−1, which makes T-LPFGs sensitive bending sensors. [ABSTRACT FROM AUTHOR]

Chronic energy restriction (ER) dramatically enhances intestinal absorption of nutrients by aged mice. Do adaptations in nutrient absorption develop only after extended ER or immediately after its initiation? To determine the time course of adaptations, we measured rates of intestinal glucose, fructose and proline transport 1-270 d after initiation of ER (70% of ad libitum) in 3-mo old mice. Mice of the same age that consumed food ad libitum (AL) served as controls; a third group was starved for 1 or 2 d only, to distinguish the effects of acute ER from those of starvation. Acute ER of 1, 2 and 10 d had no effect on nutrient absorption. Starvation significantly decreased intestinal mass per centimeter, thereby reducing transport per centimeter and intestinal absorptive capacity without significantly altering transport per milligram of intestine. ER for 24 d enhanced only fructose uptake, whereas ER for 270 d enhanced uptake of all nutrients by 20-100%. Despite marked differences in body weights, the wet weights of the stomach, small intestine, cecum and large intestine were generally similar in AL and ER mice, suggesting that the gastrointestinal tract was spared during ER. In contrast, the wet weights of the lungs, kidneys, spleen, heart, pancreas and liver each differed by 40-120% between ER and AL mice. Intestinal transport adaptations develop gradually during ER, and the main mechanism underlying these adaptations is a dramatic increase in transport activity per milligram tissue. [ABSTRACT FROM AUTHOR]

Circulating tumor DNA (ctDNA) is cell-free DNA released by tumors or circulating tumor cells, containing abundant tumor-specific information that can serve as biomarkers for cancer early screening, monitoring, prognosis, and prediction of treatment response. This is particularly attractive in the field of gastric cancer, where high-quality screening, monitoring, and prediction methods are currently lacking. Gastric cancer exhibits significant tumor heterogeneity, with large differences in genetic and epigenetic characteristics among different subgroups. Methylated ctDNA has high sensitivity and specificity, which can help clarify tumor genotyping and facilitate the formulation of precise diagnostic and therapeutic strategies. Furthermore, numerous studies have confirmed the unique advantages of methylated DNA in predicting treatment response, adjuvant therapy, and drug resistance assessment, which may be used in the future to enhance the efficacy of chemotherapy regimens and improve patient chemotherapeutic response, and even treat multidrug resistance. However, there are several challenges associated with methylated ctDNA, such as low sensitivity and specificity at single-target sites, limited association between some gastric cancer subtypes and ctDNA, off-target risks, and the lack of large-scale and high-quality clinical research evidence. This review mainly summarizes current research on the methylation status of ctDNA in gastric cancer and connects these findings to early screening, recurrence monitoring, and potential treatment opportunities for gastric cancer. With advances in technology and the deepening of interdisciplinary research, ctDNA detection will reveal more disease information and become an essential foundation for gastric cancer research and precision medicine treatment.

Rectal cancer is the most common tumor of digestive tract. For female patients, ovarian metastasis ranks the second place in intraperitoneal organ metastasis. Its symptoms are occult, easily missed and insensitive to systemic treatment, so the prognosis is poor. Surgery is the treatment of choice for patients with rectal ovarian metastases, whether R0 resection is possible or not, and reducing tumor load is associated with better prognosis. With the continuous development of hyperthermic intraperitoneal chemotherapy (HIPEC), tumor reduction can reach the cellular level, which can significantly improve survival. Prophylactic ovariectomy remains a controversial issue in patients at high risk of ovarian metastasis. In this review, we summarize the diagnosis, treatment and prevention strategies of rectal cancer ovarian metastases, hoping to provide some reference for clinical practice.

From November 1986 to June 1991, 91,683 neonates were screened for congenital hypothyroidism by measuring thyroid-stimulating hormone (TSH). 10,284 neonates were screened with chemical luminoimmunoassay (CLIA), and 80,399 screened with time-resolved fluoroimmunoassay (DELFIA). The critical value of TSH was 20 mU/L. Twenty cases were confirmed to be congenital hypothyroidism. The incidence was 1:4584, with a female to male ratio of 3:2. These patients were treated with thyroid gland desiccant, with a dosage equivalent to L-thyroxin 5-7.5 micrograms/kg/day. Their physical growth and intellectual ability were normal. 81,201 dried blood specimens were tested in single for TSH by DELFIA and T4, T3 and TSH serum testing for those with elevated TSH. No false negative and missing case was found after the screening program started. When frequent fluctuation of T4 and TSH concentration occurred at normal level in some infants, it is better to wait and have a close observation, however the treatment must be started before 3 months of age to avoid the risk of mental retardation.

Clinical, radiological and CT manifestations of 36 patients with lumbar posterior marginal intraosseous cartilaginous node (LPMN) were analysed. Of the 36 patients, 27 were male and 9 female, most of them were young adults. The posteroinferior margin of L4 was the commonest site and the posterosuperior margin might also be involved. Two patients had multiple lesions. Typical radiological findings included a defect in the posteroinferior (or posterosuperior) margin of the affected vertebral body and behind the defect a bony ridge protruding into the spinal canal. CT scan showed a cartilaginous node in the posterior zone of the vertebral plate. It is suggested that LPMN was the result of disc material herniating into the posterior aspect of vertebral body through ruptured cartilaginous end-plate during the adolescence, similar to that of the limbus vertebra. Hyperflexion and hyperextension of the spine probably play an important role in the pathogenesis. The existence of LPMN favours posterior disc herniation in the same disco-vertebral junction.