A puzzling case report of well-differentiated neuroendocrine tumor mixed with gastric adenocarcinoma of the fundic gland type associated with autoimmune gastritis.

Gastric adenocarcinoma of the fundic gland type (GA-FG) is a rare gastric neoplasm. We present a unique case of multiple GA-FG that coexisted with the well-differentiated neuroendocrine tumors in a patient with autoimmune gastritis. To our knowledge, this is the first documented instance of such a co-occurrence and the molecular mechanism of their origin has been reviewed systematically. A 47-year-old male presented to our hospital with abdominal distension for over 10 years. Gastroscopy revealed multiple gastric eminence lesions (0.2-1.5 cm). After endoscopic mucosal resection, the pathological morphology showed mixed tumor components infiltrating into the submucosa with puzzling similarity. One with uniform-sized tumor cells arranged in nests or tubes and the other a well-differentiated tubular adenocarcinoma with irregular branching and visible gland fusion. Immunohistochemistry findings revealed the first component expressed typical markers of neuroendocrine tumor, whereas the second component expressed pepsinogen and mucin-6, indicating the presence of oxyntic gland adenocarcinoma. Due to the tumors' proximity to the surgical margins, the patient underwent laparoscopic subtotal gastrectomy three months after the diagnosis without any tumor residue and showed no recurrence or metastasis occurred in the following regular checkups.

Femtosecond Yb-doped tapered fiber pulse amplifiers with peak power of over hundred megawatts.

Ultrafast fiber lasers combining high peak power and excellent beam quality in the 1-µm wavelength range have been explored to applications in industry, medicine and fundamental science. Here, we report generation of a high-energy sub 300 fs polarization maintaining fiber chirped pulse amplification (CPA) system by using a Yb-doped large mode area tapered polarization maintaining (PM) optical fiber with the core/cladding diameters of 35/250 µm at the thin end and 56/400 µm at the thick end. The taper fiber design features a confined core for selective gain amplification and multi-layer cladding for enhanced suppression of higher order modes. In this regime, we have demonstrated 266 fs pulse amplification with peak power of up to 132 MW at a repetition rate of 2 MHz and high beam quality with measured M2 value of 1.1∼1.3. To the best of our knowledge, it is the highest peak power reported in such tapered Yb-doped fiber (T-YDF) amplifier in the femtosecond regime. This work indicates the great potential of the T-YDF to realize further power scaling, high laser efficiency, and excellent beam quality in high-power femtosecond fiber lasers.

Efficacy and prognosis analyses of apatinib combined with S-1 in third-line chemotherapy for advanced gastric cancer.

PURPOSE: To explore the efficacy and safety of apatinib (an anti-angiogenic drug) combined with S-1 (a fluorouracil drug) in the third-line chemotherapy for advanced gastric cancer, and to analyze the factors influencing the prognosis. METHODS: Eighty-four patients with advanced gastric cancer, who did not respond to second-line or above chemotherapy and were treated in our hospital were enrolled and divided into Apatinib+S-1 group (n=42) and S-1 group (n=42), based on different treatments applied. Next, the clinical responses and adverse reactions of patients were observed and recorded. The patients were followed up through the outpatient service and telephone to record their survival and disease progression. Additionally, the factors affecting the prognosis of patients were analyzed. RESULTS: The objective response rate (ORR) and disease control rate (DCR) in the Apatinib+S-1 group were 9.5% (4/42) and 71.4% (30/42), respectively, which were significantly higher than those in the S-1 group. The main adverse reactions after therapy included neutropenia, thrombocytopenia, anemia, stomatitis, hypertension, proteinuria, hand-foot syndrome and gastrointestinal reaction, which were mostly of grade I-II. The incidence rates of hypertension, proteinuria and hand-foot syndrome were 42.9%, 26.2%, and 23.8%, respectively, in the Apatinib+S-1 group, which were overtly higher than those in the S-1 group. There was no statistically significant difference in the overall survival (OS) of patients between two groups (p=0.063), while the progression free survival (PFS) of patients was overtly longer in the Apatinib + S-1 group than that in S-1 group. Univariate analysis of PFS showed that the PFS of patients with high differentiation of tumor or post-treatment proteinuria or hand-foot syndrome was evidently higher than that of patients without high differentiation of tumor or post-treatment proteinuria or hand-foot syndrome. CONCLUSION: Patients with advanced gastric cancer achieve relatively satisfactory short-term therapeutic effects after treatment with apatinib combined with S-1 in the third-line therapy, whose PFS is notably better than those treated with S-1 alone, and they are tolerant to adverse reactions. Highly differentiated tumors and post-treatment proteinuria and hand-foot syndrome are predictable factors for the PFS of patients.

A compact large-format streak tube for imaging lidar.

The streak tubes with a large effective photocathode area, large effective phosphor screen area, and high photocathode radiant sensitivity are essential for improving the field of view, depth of field, and detectable range of the multiple-slit streak tube imaging lidar. In this paper, a high spatial resolution, large photocathode area, and compact meshless streak tube with a spherically curved cathode and screen is designed and tested. Its spatial resolution reaches 20 lp/mm over the entire Φ28 mm photocathode working area, and the simulated physical temporal resolution is better than 30 ps. The temporal distortion in our large-format streak tube, which is shown to be a non-negligible factor, has a minimum value as the radius of curvature of the photocathode varies. Furthermore, the photocathode radiant sensitivity and radiant power gain reach 41 mA/W and 18.4 at the wavelength of 550 nm, respectively. Most importantly, the external dimensions of our streak tube are no more than Φ60 mm × 110 mm.