Bangladesh Railway EPC Track Engineering Investigation and Summary

Bangladesh’s railway infrastructure is outdated and inadequate, and the lack of transportation capacity seriously hinders the country’s economic development. In the track engineering practice of EPC projects such as the second line project of a railway Meter-Gauge addition project and the new Board-Gauge railway project in Bangladesh, according to the operation characteristics and maintenance status of the existing cable of the Bangladesh railway, the design and construction characteristics of the railway track, and the procurement of track materials, combined with the characteristics of the EPC project management in the country, suggestions on the general contracting and construction of track engineering were put forward. He also analyzed and summarized the risk factors in the design and construction of Bangladesh railway track engineering, and made some useful thoughts and explorations on how to do a good job in the general contracting of track engineering of EPC projects according to local conditions

Long-term outcomes of anatomic vs. non-anatomic resection in intrahepatic cholangiocarcinoma with hepatolithiasis: A multicenter retrospective study

BackgroundThe benefits of anatomic resection (AR) vs. non-anatomic resection (NAR) in patients with primary intrahepatic cholangiocarcinoma (ICC) with hepatolithiasis (HICC) are unclear. This study aimed to compare the long-term outcomes of AR vs. NAR in patients with HICC.MethodsA total of 147 consecutive patients with HICC who underwent R0 hepatectomy were included. Overall survival (OS) and recurrence-free survival (RFS) following AR vs. NARs were compared using a 1:1 propensity score matching (PSM) analysis. A subgroup analysis was also conducted according to whether there are lymph node metastases (LNM).ResultsIn a multivariate analysis, CA 19-9 (>39 U/L), microvascular invasion, LNM, and NAR were independent risk factors for poor RFS and OS rates, whereas multiple tumors were independent risk factors for OS. AR had better 1-, 3-, and 5-year RFS and OS rates than NAR (OS: 78.7, 58.9, and 28.5%, respectively, vs. 61.2, 25.4, and 8.8%, respectively; RFS: 59.5, 36.5, and 20.5%, respectively, vs. 38.2, 12.1, and 6.9%, respectively). After PSM, 100 patients were enrolled. The NAR group also had significantly poorer OS and RFS (OS: 0.016; RFS: p = 0.010) than the AR group. The subgroup analysis demonstrated that in HICC without LNM, OS and RFS were significantly poorer in the NAR group than the AR group, while no significant differences were observed in HICC with LNM before or after PSM.ConclusionAnatomic resection was associated with better long-term survival outcomes than NAR in patients with HICC, except for patients with LNM

Clinicopathologic features and outcomes following surgery for pancreatic adenosquamous carcinoma

<p>Abstract</p> <p>Background</p> <p>Pancreatic adenosquamous carcinoma (ASC) is a rare pancreatic malignancy subtype. We investigated the clinicopathological features and outcome of pancreatic ASC patients after surgery.</p> <p>Methods</p> <p>The medical records of 12 patients with pancreatic ASC undergoing surgical treatment (1993 to 2006) were retrospectively reviewed. Survival data of patients with stage IIB pancreatic adenocarcinoma and ASC undergoing surgical resection were compared.</p> <p>Results</p> <p>Symptoms included abdominal pain (91.7%), body weight loss (83.3%), anorexia (41.7%) and jaundice (25.0%). Tumors were located at pancreatic head in 5 (41.7%) patients, tail in 5 (41.7%), and body in 4 (33.3%). Median tumor size was 6.3 cm. Surgical resection was performed on 7 patients, bypass surgery on 3, and exploratory laparotomy with biopsy on 2. No surgical mortality was identified. Seven (58.3%) and 11 (91.7%) patients died within 6 and 12 months of operation, respectively. Median survival of 12 patients was 4.41 months. Seven patients receiving surgical resection had median survival of 6.51 months. Patients with stage IIB pancreatic ASC had shorter median survival compared to those with adenocarcinoma.</p> <p>Conclusion</p> <p>Aggressive surgical management does not appear effective in treating pancreatic ASC patients. Strategies involving non-surgical treatment such as chemotherapy, radiotherapy or target agents should be tested.</p

Isolated pancreatic metastasis from rectal cancer: a case report and review of literature

Isolated pancreatic metastases from a non-pancreatic primary malignancy are very rare. Studies have shown that resection of metastases is of proven benefit in some types of tumors. We report a case of 76-year-old Taiwanese woman with rectal adenocarcinoma treated with neoadjuvant chemoradiotherapy and abdominoperineal resection 2 years ago presenting with an asymptomatic mass at the pancreatic tail on a routine follow up abdominal computed tomography scan. The patient underwent distal pancreatectomy and splenectomy under the preoperative impression of a primary pancreatic malignancy. Histological examination of the surgical specimen showed metastatic adenocarcinoma. Immunohistochemical studies confirmed the diagnosis of pancreatic metastasis from rectal adenocarcinoma. Postoperative chemotherapy in the form of oral capecitabine was given. The patient is alive and disease free 12 months after the surgery. In a patient presenting with a pancreatic mass with history of a non-pancreatic malignancy, a differential diagnosis of pancreatic metastasis should be considered. Surgical resection of a solitary pancreatic mass is justified not only to get the definitive diagnosis but also to improve the survival

Dopant clustering, electronic inhomogeneity, and vortex pinning in iron-based superconductors

We use scanning tunneling microscopy to map the surface structure, nanoscale electronic inhomogeneity, and vitreous vortex phase in the hole-doped superconductor Sr0.75K0.25Fe2As2 with Tc=32 K. We find that the low-T cleaved surface is dominated by a half Sr/K termination with 1×2 ordering and ubiquitous superconducting gap, while patches of gapless, unreconstructed As termination appear rarely. The superconducting gap varies by σ/Δ¯=16% on a ∼3 nm length scale, with average 2Δ¯/kBTc=3.6 in the weak-coupling limit. The vortex core size provides a measure of the superconducting coherence length ξ=2.3 nm. We quantify the vortex lattice correlation length at 9 T in comparison to several iron-based superconductors. The comparison leads us to suggest the importance of dopant size mismatch as a cause of dopant clustering, electronic inhomogeneity, and strong vortex pinning.Physic

Pyrite textures and compositions in Jiangshan gold deposit, Bengbu Uplift, southeastern North China Craton: Implications for ore genesis

Many Phanerozoic gold deposits in East China, e.g., those in the Jiaodong Peninsula, hosted either in granitoids of the same age or Precambrian basement rocks of the North China Craton, have been well documented. The Bengbu Uplift along the southeastern margin of the North China Craton is believed to be the western extension of the Jiaodong gold province, separated by the large-scale sinistral Tan-Lu Fault Zone. However, no deposits with more than 10 t gold resources have been discovered in the Bengbu Uplift, and it is unclear whether the timing and genesis of gold deposits in the Bengbu Uplift are similar to those in the Jiaodong gold province. In this study, laser ablation inductively coupled plasma mass spectrometry trace element analyses, mapping, and in situ sulfur isotope analyses were used to determine the source and process of gold mineralization in Jiangshan gold deposit, the largest in the region. The wall rocks in the Jiangshan gold deposit are metamorphic rocks of the Neo-Archaean Wuhe Group, and the ore bodies are controlled by the eastern part of the Guangou–Xiajijia Fault. Four stages were identified from cross-cutting relationships and textural and mineralogical characteristics: pre-ore stage (stage I), quartz–pyrite–muscovite alteration (stage II), pyrite–quartz veins (stage III), and quartz–pyrite veinlets (stage IV). Each of the four stages is characterized by a different type of pyrite, here named Py1, Py2, Py3 and Py4. Py1 formes the core of Py2, has elliptical and irregular shapes, contains low gold and arsenic concentrations, and has δ34S values of 0.86–2.86‰. Py2 is hosted in quartz–- pyrite–muscovite-altered rocks with disseminated and aggregated euhedral to subhedral textures. It has elevated arsenic content and the lowest gold content, with some rhythmic zones and fractures. Stage II was crosscut by stage III. Py3 has anhedral textures with brittle deformation and occupies fractures in stage III pyrite–quartz veins. The gold content of Py3 is slightly higher than that of Py1 and Py2, but its arsenic content is extremely low. Py4 in the quartz–pyrite veinlets has cataclastic textures with the highest gold and chalcophile element contents. Native gold and electrum also formed in stage IV, which is the main gold stage in the Jiangshan deposit. The δ34S values of Py2–Py4 are broadly similar (5.79–7.98‰), suggesting a common sulfur source. Based on previous studies and higher δ34S values of hydrothermal pyrite, the fluid sulfur isotopes are interpreted to relate to degassing of the mantle wedge metasomatized by slab fluids during the westward subduction of the palaeo-Pacific plate beneath the North China Craton during the early Cretaceous. Based on the geological characteristics of the deposit, we classify the Jiangshan gold deposit as a Jiaodong fracture-disseminated-type gold deposit which occurs as disseminated veinlets and disseminated mineralization in wallrocks along fracture zones. Tectonic events may be the most important factor in gold mineralization in fracture-disseminated type gold deposits.This work was financially supported by the National Key Research and Development Plan (grant No. 2016YFC0600206), the National Natural Science Foundation of China (grant No. 41672081), and the Public Welfare Project of Anhui Province (grant No. 2016-g-3-35)