Obvious Source Research Articles

EVIDENCE-BASED MEDICINE AS PATIENT'S PROTECTION MEASURE IN JUDICIAL PRACTICE

The aim: To identify the role of evidence-based medicine, its principles and approaches to patients' rights protection and the provision of medical service optimization, the skills of medical staff improvement, increasing the objectivity of court decisions in cases of non-providing quality care or death. Materials and methods: The authors used the decisions by the European Court of Human Rights (ECtHR) on the statements of victims of unprofessional actions by doctors, international and domestic regulations on patients' rights, statistics on the results of criminal proceedings on violations of patients' rights over the past 5 years, case law of criminal and civil jurisdiction in this category of cases, the results of surveys of prosecutors, as well as the results of research by scientists in the field of medical law and criminalistics. The research is carried out on the basis of a harmonious combination of philosophical approaches, general scientific and special methods of scientific knowledge, the complex of which is chosen taking into account the goals and objectives, object and subject of research. Conclusions: In order to implement the patients' rights by legal means in accordance with the Convention for the Protection of Human Rights and Fundamental Freedoms, the European Charter of Patients' Rights and other international regulations in the field of medicine, the authors argue the need for greater implementation of evidence-based medicine into the practice of medical institutions as a means of improving the level of medical care and an obvious source of relevant information for litigation to protect the rights of patients and doctors. For patients' rights protection in the diagnosis and treatment of diseases, it is proposed to regulate a set of such measures: 1) to include in the educational programs of pharmacy and medicine such disciplines as «Evidence-Based Medicine» and «Rights of the patient and medical worker's rights»; 2) to oblige the doctor to explain to the patient or to his/her representative the differences of treatment protocols, to provide information to patients about official sources, which contain information on unified and updated treatment protocols and diagnosis of certain diseases, to obtain informed consent by the patient (his/her representative) on certain medical guideline; 3) to recognize medical guidelines as sources of law in criminal and civil proceedings as a kind of benchmarks for clarifying and assessing the facts of non-performance or improper performance of professional duties by a medical or pharmaceutical worker, violation of patients' rights, as well as means for doctors' legal protection and etc.

Use of multiple isotopic and chemical tracers to identify sources of nitrate in shallow groundwaters along the northern slope of the Qinling Mountains, China

Isotopes and major ion hydrochemistry are used to investigate potential sources of nitrate contamination in shallow aquifers along the northern slope of the Qinling Mountains, west-central China. Locally, nitrate concentrations exceed a remarkable 850 mg/L, over 40 times background levels observed in fresh mountain springs, and a knowledge and understanding of the nitrate pollution sources is essential for the development of aquifer management and protection strategies that will allow the problem to be effectively controlled. Presently, none of the suspected pollutant sources generates concentrations of nitrate that even approach levels observed in the groundwater, and this is clearly a challenge in terms of assigning responsibility for the contamination and developing appropriate management plans. However, stable isotopes of hydrogen and oxygen (δD and δ18O) in study area waters demonstrate that the centrally located Jijiahe Reservoir and Shidi River have been a major source of aquifer recharge in recent times and are an obvious source of the contamination. Moreover, δ15N–NO3– and δ18O–NO3– determinations suggest that, while nitrate concentrations in the river and reservoir are currently relatively low, a local, long-established fertilizer factory that has likely released high-nitrogen waste to these nearby receptors in the past, is the primary pollutant source. On a positive note, it would appear that the majority of the nitrate contamination, albeit serious in terms of drinking water quality, represents a legacy of past practice and should show gradual improvement due to modern-day environmental protection initiatives, improved equipment, better monitoring and significantly enhanced methods of wastewater treatment. However, the isotope data do indicate that the aquifer continues to be impacted by other anthropogenic activities, including agriculture and livestock raising, downstream of the industrial area and in the eastern part of the study area, meaning that monitoring and active remediation strategies need to be continued with vigilance.

Recent developments in selective catalytic conversion of lignin into aromatics and their derivatives

Lignin (15–30 wt%) is a key component of lignocellulosic biomass, along with cellulose (30–50 wt%) and hemicellulose (20–35 wt%), which is largely obtained as a waste product from pulp/paper and biorefinery industries. Due to its aromatic polymer structure, lignin is an obvious non-fossil source for aromatics and their derivatives. Efficient lignin valorization can assist in achieving two essential energy goals, i.e., boosting the lignocellulosic biorefinery and reducing the utilization of fossil fuels for chemicals synthesis. Hence, developing efficient processes and technologies for transforming this waste lignin into value-added chemicals is of paramount interest in the current biorefinery research. Catalysis plays a crucial role in lignin valorization via efficient cleavage of C-O and C-C bonds, which is greatly dependent on the catalysts’ properties and the reaction conditions. In this mini review, we provided a concise account of the most important catalytic routes recently developed for the efficient cleavage of C-O and C-C linkages in lignin systems to produce desired aromatics and their derivatives. Strategies to control unwanted cracking of lignin and char formation especially during catalytic hydroprocessing of lignin are critically discussed. Special attention has been dedicated to understand the role of acid and redox properties of heterogeneous solid catalysts in the selective depolymerization/upgrading of lignin systems.

751. Study on Daptomycin Prescription Suitability as a First Step Towards an Antimicrobial Stewardship Program

BackgroundDaptomycin use has increased since its approval and has often extended to indications not included in the summary of product characteristics with highly variable dosing. Our objective was to assess daptomycin real use in an institution with Pharmacy and ID consultation available and to explore the need for establish specific Daptomycin stewardship.MethodsObservational, retrospective study including all patients treated with daptomycin during 2017 in a tertiary hospital. Clinical variables were collected in a pre-established protocol including demographics, comorbidities, infection type, microbiological results, adverse events (AE), outcomes, and treatment adequacy (selection, dosage, microbiological adjustment and duration). Daptomycin prescription is not restricted at our institution. The dosages were considered adequate according to clinical guidelines.ResultsOverall 176 patients (62% men, median age: 70years) started treatment with daptomycin, 58% of them on empirical bases. Main uses were: skin and soft-tissue infections (37.5%), fever without obvious source (17.6%) and osteoarticular infection (12.5%). Sixty-three patients (35.8%) had concomitant bacteremia. An etiologic diagnosis was reached in 89.2% patients and S.aureuswas the most frequently isolated microorganism (n = 58, and 10 MRSA), followed by CoNS (n = 35). Overall, 77.7% of patients evolved satisfactorily. Five patients discontinued treatment due to AE (urticaria, cholestasis, increased CPK and rhabdomyolysis). Infection-related mortality was 7.4%. Daptomycin was correctly selected in 94.3% patients, length of therapy was adequate in 87.4%. However, only 47.1% of patients received adequate dosage (underdosing in 27.8%) and in 9.8% of patients, the treatment was not adjusted according to microbiological results. The prevalence of daptomycin use was 3.7 patients/1,000 admissions.ConclusionDaptomycin is often prescribed empirically, using nonadequate dosages and duration of therapy needs also an improvement. The follow-up of patients treated with daptomycin should be considered a priority intervention within an Antimicrobial Stewardship Program.Disclosures All authors: No reported disclosures.

2460. Hospital-Wide Outbreak of Serratia marcescens of Unclear Source: When Extensive Infection Control Measures Are Needed

BackgroundNosocomial outbreaks of Serratia marcescens have been widely reported and the source is identified in most cases. We report a Serratia marcescens outbreak in a community hospital with no obvious source.MethodsAn epidemiologic investigation was started after an outbreak was suspected. Clinical data were collected from charts of patients with positive culture for Serratia marcescens. Molecular relatedness of available isolates was determined by pulsed-field gel electrophoresis.ResultsBetween December 2016 and August 2017, 13 non-pigmented Serratia marcescens isolates were identified from 11 patients. Bacteria were isolated from blood, abdominal and respiratory cultures. Susceptibility profiles showed variable resistance to ceftriaxone, ceftazidime, imipenem, tobramycin and aztreonam. Infection control measures: Isolates were identified from adult patients who underwent various cardiothoracic/vascular surgeries. Patients were traced back to a single floor of the new hospital building. To control this outbreak, the infection prevention team started with hand hygiene initiatives and observations, environmental sampling, and reviewing management of ventilator, dialysis equipment, and ECMO machines. Ice machine carbonless filters were installed, UV disinfection systems were used, and new TEE cleaning rooms were designated. In conjunction with recommendations of department of health, hospital was contracted with a water cleaning company; laminar flow aerators were installed, water sampling plan was implemented and ultimately the whole building’s water system was hyper-chlorinated.ConclusionWhile water contamination was the most likely source, a specific cause could not be identified. An important lesson learnt is the quick implementation of infection control measures after identifying infected patients is key in controlling an outbreak.Disclosures All authors: No reported disclosures.

Morbidity Following Hand-Assisted Laparoscopic Donor Nephrectomy.

Background: The incidence of morbidity and readmission rate after hand-assisted laparoscopic donor nephrectomy (HALDN) is not clear. Aims: Our study aims to review our experience with HALDN, mainly the reasons for patient readmissions. Methods: Prospectively collected data on all patients undergoing HALDNs between August 2007 and June 2015 were retrieved. The primary outcome was 30-day readmission rate. Secondary outcomes were complications and readmission etiology. Results: There were 161 nephrectomies with a median age of 51 years, 72 (44.7%) men, and 114 (70.8%) left-sided operations. Twenty-one (13%) individuals were readmitted within 30 days. There were total 25 (15.5%) readmissions during the study period. The characteristics of patients readmitted and patients not readmitted were broadly similar. Nine of 21 (43%) individuals readmitted had nonspecific findings (nonspecific findings on imaging, negative blood cultures, and raised inflammatory markers). The reasons for readmission were unrelated to nephrectomy in 24% and 19% required surgery for complications unrelated to nephrectomy. Conclusion: We observed a high readmission rate after HALDN. A significant proportion of readmissions were due to nonspecific abdominal pain associated with raised inflammatory markers and no obvious source of sepsis. Living donors should be fully informed about the risks including the possibility of complications unrelated to HALDN.

Tongue base varix as a source of oral bleeding

Rationale:Oral bleeding is usually diagnosed after by referral to other department for the differential diagnosis of hematemesis or hemoptysis. If a patient presents with blood in the oral cavity with no obvious source, generally upper airway, pulmonary, or gastroesophageal lesions are considered likely bleeding foci. The tongue base is an unusual site for laryngopharyngeal varices and only a few cases have been reported.Patient concerns:Although varix at the tongue base in patients with liver cirrhosis has been rarely described, physicians must consider variceal bleeding from the tongue base when presented with oral bleeding. In such cases, bleeding foci can be identified and controlled by laryngoscopy. We describe the case of a 42-year-old woman complaining of small amount of hemoptysis with variceal bleeding at the tongue base controlled by laryngoscopic excision and cauterization.Diagnosis:A diagnosis of tongue base varix was made based on medical history, clinical manifestations, laryngoscopic findings and pathologic features for the patient.Interventions:The successful laryngoscopic procedures were performed.Outcomes:The patient has shown no recurrent oral bleeding during follow-up.Lessons:Variceal bleeding in the tongue base is likely to cause serious massive hemorrhage. We need to consider this possibility when presented with a patient with intraoral bleeding but no evidence of hemoptysis or hematemesis.

1751 A Rare Complication of a Common Finding: A Case of Iron Deficiency Anemia Secondary to an Ulcerated Inlet Patch

INTRODUCTION: Inlet patches are a congenital anomaly of the cervical esophagus which are comprised of heterotropic gastric mucosa and have been reported in 1-12% of patients on endoscopy. Typically, this finding is seen distal to the upper esophageal sphincter, and appears endoscopically as a salmon colored patch which contrasts against normal esophageal mucosa. Rarely, inlet patches become symptomatic due to mucosal changes leading to ulceration, neoplasia or stricturing. We present a case of an ulcerated inlet patch leading to iron deficiency anemia. CASE DESCRIPTION/METHODS: The patient was a 41 year old African American female, who was admitted with a cardioembolic stroke (CVA). On admission, hemoglobin was noted to be 5.8 g/dL with an MCV of 55 fl. Her iron panel was suggestive of iron deficiency anemia (TIBC 455 ug/dL, Ferritin 5 ng/ml, Iron Saturation 4.4%). She denied having gastrointestinal symptoms, overt bleeding and she endorsed only having light bleeding during menstruation. EGD and colonoscopy were performed to further evaluate her anemia. Colonoscopy with intubation of the terminal ileum was unremarkable however, EGD revealed an ulcerated gastric inlet patch with adherent clot at 20 cm from incisors. No other obvious bleeding source was identified on EGD. Given her recent initiation of anticoagulation for cardioembolic stroke and absence active bleeding, the decision was made to not perform any endoscopic interventions. She was started on a proton pump inhibitor and serology for Heliobacter pylori (HP) IgG obtained. When this returned was positive she was initiated on triple therapy. DISCUSSION: This represents a rare case of an ulcerated gastric inlet patch resulting in iron deficiency anemia. Literature suggests that there may be high concordance of Helicobacter pylori colonization of inlet patches in patients with colonization of the stomach. Potentially this could be a unifying diagnosis of her HP serology positivity and an ulcerated inlet patch. This case also highlights the importance of deliberate visualization of the esophagus during EGD where proximal esophageal lesions can be easily missed.

IntaRNAhelix-composing RNA-RNA interactions from stable inter-molecular helices boosts bacterial sRNA target prediction.

Efficient computational tools for the identification of putative target RNAs regulated by prokaryotic sRNAs rely on thermodynamic models of RNA secondary structures. While they typically predict RNA-RNA interaction complexes accurately, they yield many highly-ranked false positives in target screens. One obvious source of this low specificity appears to be the disability of current secondary-structure-based models to reflect steric constraints, which nevertheless govern the kinetic formation of RNA-RNA interactions. For example, often- even thermodynamically favorable- extensions of short initial kissing hairpin interactions are kinetically prohibited, since this would require unwinding of intra-molecular helices as well as sterically impossible bending of the interaction helix. Another source is the consideration of instable and thus unlikely subinteractions that enable better scoring of longer interactions. In consequence, the efficient prediction methods that do not consider such effects show a high false positive rate. To increase the prediction accuracy we devise IntaRNAhelix, a dynamic programming algorithm that length-restricts the runs of consecutive inter-molecular base pairs (perfect canonical stackings), which we hypothesize to implicitly model the steric and kinetic effects. The novel method is implemented by extending the state-of-the-art tool IntaRNA. Our comprehensive bacterial sRNA target prediction benchmark demonstrates significant improvements of the prediction accuracy and enables more than 40-times faster computations. These results indicate- supporting our hypothesis- that stable helix composition increases the accuracy of interaction prediction models compared to the current state-of-the-art approach.

3144 Dieulafoy Lesions: A Rare Case of Recurrence

INTRODUCTION: Dieulafoy lesions (DL) are thickened arteriole malformations commonly found in the stomach that account for less than 2% of acute gastrointestinal (GI) bleeds. Conventional treatment is endoscopic and rarely requires surgical intervention. The risk of recurrence is low, especially in previously treated patients. CASE DESCRIPTION/METHODS: A 59-year-old male with past medical significant for hypertension (HTN), previous DL treated with gastrectomy for recurrent bleeding and multiple packed red blood cell (pRBC) transfusion 18 years ago presented for evaluation of palpitations. Review of system was positive for melena and lightheadedness with unremarkable physical examination. The patient was not on anticoagulation or anti-platelet agents. Laboratory test resulted in a hemoglobin (Hgb) of 8 g/dL. Upper endoscopy revealed non-bleeding ulcers in the stomach and colonoscopy revealed three polyps with no obvious source of bleeding. Hgb continued to trend downward and patient required multiple pRBC transfusions. Capsule endoscopy was performed at discharged, but patient was readmitted for a repeat episode of melena. Result of the capsule endoscopy revealed a clot in stomach with active bleeding in duodenum. Repeat endoscopy showed a DL in the proximal stomach which required placement of three clips to control the hemorrhage. Patient was discharged on omeprazole with no recurrent symptoms. DISCUSSION: DL are arterioles with thickened caliber that can protrude through a defect in the submucosal base without signs of ulceration. The pathogenesis is not clear, but likely secondary to a congenital abnormality of the blood vessels or a thrombotic event of the arteriole causing necrosis. The distribution of DL is equal in all ages but has a male predominance. Risk factors include heart disease, use of anticoagulants or anti-platelet agents and alcohol exposure; However, the mechanism by which they exert their effect is controversial. Surgery was the preferred treatment for DL, but now is less common with more endoscopic techniques available. Our patient had certain risk factors that could have led to his original lesions, such as hypertension. The risk of recurrence following endoscopic treatment is less than 9% and less with surgical resection, which would suggest an underlying contributing factor. DL need to be included in the differential diagnosis for GI bleeding, even in previously treated patients, given there are underlying factors that have yet to be elicited contributing to recurrence.

2009 Bleeding Intestinal Lymphangiectasia Diagnosed and Treated by Using Double Balloon Enteroscopy in a 41-Year-Old Female: Case Report and Review of Literature

INTRODUCTION: Intestinal lymphangiectasia (IL) is a rare disease characterized by dilated lymphatic vessels in the intestinal wall and small bowel mesentery, which induce loss of protein and lymphocytes into the bowel lumen. Gastrointestinal bleeding (GIB) rarely has been described as the only symptom of IL. We describe a case of obscure GIB in a young female caused by lymphangiectasia localized to the distal jejunum by antegrade double balloon enteroscopy. CASE DESCRIPTION/METHODS: A 41-year-old African American female who initially presented to her PCP with chronic fatigue and intermittent episodes of melena. The patient was subsequently placed on iron supplementation and referred to gastroenterology for further work up. Physical examination finding were largely unremarkable. On laboratory tests, her hemoglobin declined to 5.8 g/dL (from a baseline of 10 g/dL). Initial Esophagogastroduodenoscopy (EGD) showed 2 cm hiatal hernia but was otherwise unremarkable. A subsequent colonoscopy showed mild internal hemorrhoids and a 3 mm solitary ulcer in the distal rectum but no other obvious sources of GI bleeding. Magnetic resonance enterography (MRE) was unremarkable. Next, a video capsule endoscopy was done which showed a site of active bleeding from the mid-small bowel and was associated with nodular mucosa and prominent lacteals. A subsequent double balloon enteroscopy (DBE) showed an oozing fold in the distal jejunum with white speckled appearance consistent with a bleeding lymphangiectasia. A total of seven clips were placed on the lesion and during application of clips, a white milky substance was noted coming from the lesion suggesting the diagnosis of lymphangiectasia. DISCUSSION: IL is most commonly found in the small bowel, making its diagnosis difficult by EGD or colonoscopy. DBE and video capsule endoscopy (VCE) are the two most important diagnostic modalities available to evaluate the entire small intestine.The noninvasive nature of VCE and its capability to visualize the entire small bowel has made it a first-line tool in many centers. However, DBE is preferred over video capsule endoscopy because of higher sensitivity from better endoscopic visualization and ability to perform biopsies for pathologic diagnosis. In this report, we present an extremely rare case of primary intestinal lymphangiectasia in causing obscure GIB and successful intervention using DBE. We believe this is the second case to report small bowel bleeding from jejunal lymphangiectasia, which was successfully treated using DBE.

2985 Low Diagnostic Yield of Routine Duodenal Biopsies in Asymptomatic Patients With Iron Deficiency Anemia

INTRODUCTION: It is estimated that 1.6 billion people worldwide are anemic. Iron deficiency anemia (IDA) is the most common form of anemia worldwide. In adults without an obvious source of blood loss, the explanation for IDA is generally thought to be due to chronic gastrointestinal blood loss. Current guidelines recommend performing both upper and lower endoscopies for patients with iron deficiency anemia. Duodenal biopsies are routinely performed to evaluate for celiac sprue as the etiology of IDA. The primary aim of this study is to determine the diagnostic yield of routine duodenal biopsies performed for investigation of asymptomatic patients with iron deficiency anemia (without malabsorption symptoms). METHODS: A retrospective chart review was performed of patients undergoing esophagogastroduodenoscopy (EGD) with duodenal biopsy as work up of IDA. All duodenal biopsies were performed from January 2011 through April 2019 at an academic tertiary referral center. Inclusion criteria was ferritin ≤45 ng/mL within 1 year prior to EGD. If ferritin data was unavailable, physician records were reviewed for diagnosis of iron deficiency anemia in patients who had proven serum MCV < 80 um3 within 1 year prior to EGD. Data was collected for asymptomatic patients, N = 250. Charts were reviewed and patients with malabsorption symptoms such as abdominal pain, weight loss, diarrhea, and bloating were excluded. In addition, patients with rectal bleeding, history of IBD, gastrointestinal cancer, lymphoma or abdominal surgery leading to malabsorption were also excluded. A diagnosis of celiac disease was defined as a Marsh type 2 or greater on tissue biopsy. RESULTS: The median age of patients was 60.6 ± 14.1 of whom 43% were female. A total of 59% of cases were Caucasian, 19% were Hispanic, 8% African American, 8% Asian and 9% other. The mean of Hgb was 9.2 ± 1.9 gm/dL, MCV, 76.4 ± 8.0% and ferritin, 21.7 ± 38.7 um3. Of the sample, 25% had DM2, 20% had CAD, 14% had CKD, 12% had atrial fibrillation and 6% had cirrhosis. The overall diagnostic yield of the duodenal biopsies was 0.4% in asymptomatic patients. CONCLUSION: These results suggest that performing routine duodenal biopsies for celiac disease in patients with IDA is low yield in asymptomatic patients. Further studies are needed to characterize which patients with IDA would benefit from a duodenal biopsy for diagnosis of celiac disease.

Reducing Variability in the Infant Sepsis Evaluation (REVISE): A National Quality Initiative

Substantial variability exists in the care of febrile, well-appearing infants. We aimed to assess the impact of a national quality initiative on appropriate hospitalization and length of stay (LOS) in this population. The initiative, entitled Reducing Variability in the Infant Sepsis Evaluation (REVISE), was designed to standardize care for well-appearing infants ages 7 to 60 days evaluated for fever without an obvious source. Twelve months of baseline and 12 months of implementation data were collected from emergency departments and inpatient units. Ill-appearing infants and those with comorbid conditions were excluded. Participating sites received change tools, run charts, a mobile application, live webinars, coaching, and a LISTSERV. Analyses were performed via statistical process control charts and interrupted time series regression. The 2 outcome measures were the percentage of hospitalized infants who were evaluated and hospitalized appropriately and the percentage of hospitalized infants who were discharged with an appropriate LOS. In total, 124 hospitals from 38 states provided data on 20 570 infants. The median site improvement in percentages of infants who were evaluated and hospitalized appropriately and in those with appropriate LOS was 5.3% (interquartile range = -2.5% to 13.7%) and 15.5% (interquartile range = 2.9 to 31.3), respectively. Special cause variation toward the target was identified for both measures. There was no change in delayed treatment or missed bacterial infections (slope difference 0.1; 95% confidence interval, -8.3 to 9.1). Reducing Variability in the Infant Sepsis Evaluation noted improvement in key aspects of febrile infant management. Similar projects may be used to improve care in other clinical conditions.

Trends in the use of echocardiography in patients with Staphylococcus aureus bacteremia: an analysis using the Nationwide Inpatient Sample data.

Infective endocarditis occurs in approximately 10%-30% of patients with Staphylococcus aureus bacteremia (SaB). Guidelines recommend echocardiography in patients with SaB and risk factors for infective endocarditis in the absence of any obvious source of infection. Herein, we explored the trends in the use of echocardiography in patients with SaB and its relationship to outcomes using a large national database. All patients with a principal discharge diagnosis of SaB were identified using the National Inpatient Sample database from 2001 to 2014. Procedure code 88.72 was used to identify echocardiography. Logistic regression models were estimated to identify the year-over-year trends in echocardiogram, predictors of use, and association with mortality. From 2001 to 2014, there were 668423 hospitalizations with SaB diagnosis and 86387 (12.9%) had echocardiogram. The rate of echocardiography increased from 10.7% in 2001 to 15.2% in 2014 (ptrend <0.001). Major predictors of echocardiogram usage were younger age, male gender, presence of sepsis, valvular or congenital heart disease, prosthetic heart valve (PHV), cardiac implantable electronic device (CIED), hemodialysis, and drug abuse. The adjusted rates of echocardiography increased from approximately 10% to 15% in hospitalizations without risk factors for IE while for high-risk groups like PHV and CIED it remained constant at 30% and 19%, respectively. Echocardiography was associated with 31% lower odds of in-hospital mortality. The increase in echocardiography rate was largely attributable to increased use in those without risk factors while usage in those with PHV and CIED remained much lower than expected. Echocardiography use was associated with lower risk-adjusted mortality. These findings require further study and confirmation.

Mineralization zoning of coal-metal deposits in China

Substantive progress has been made in extracting germanium, gallium, rare earth elements (REEs), lithium, and other metals from coal. Coal deposits are becoming important sources of many strategic metal resources. However, ore deposit theory study for coal-metal resources has not been systematic. This paper summarizes the mineralization characteristics of germanium, gallium, lithium, and REEs in coal on the basis of previous research results and field investigations, including those on seven metallogenic zones of coal metal deposits in China. Coal-germanium deposits, products of magmatic hydrothermal activity, mainly occur in low rank coal in the areas of Erlian, the Hailaer Basin, Inner Mongolia, and the Sanjiang district in the Yunnan Province. Occasionally, rich-germanium-coal can be found in other areas. Coal-gallium deposits are mainly in the Permian coal of North China, Jurassic coal of Northwest China, and late-Permian coal of South China. The accumulation of gallium in coal is closely related to aluminum-containing minerals. Coal-lithium deposits mainly occur in the Zhungeer coal field, Inner Mongolia, the Pingshuo coal field, and the Jingcheng coal field in the Shanxi Province, and some coal fields in South China. Similarly to gallium, the accumulation of lithium in coal is also closely related to aluminum-containing minerals. Coal-REE deposits mainly occur in the Early Jurassic coal of the Erlian Basin and Inner Mongolia, and Late Permian coal in South China. REEs of Erlian basin coal likely entered in ionic forms in early stages of coal or peat bog formation. REEs of South China coal are likely associated with REE-rich trass volcanic ash which deposited synchronously with peat bog accumulation. Abundant abnormal metal elements in coal are important for classification of metallogenic zones. Regional tectonic background and evolution, characteristics of stratigraphic sedimentary environment, and coal quality are also important factors. (1) Delineation of germanium metallogenic zones in the coal follows the principles that: coal in the coal area should be low-metamorphic bituminous (long-flame) coal; the basement of the coal-bearing basin was broken and faults developed in the region; and there are obvious traces of hydrothermal intrusion in or around the coal measures in the zone. (2) Delineation of gallium metallogenic zones in coal is based on these traits: an obvious gallium source should exist in the region; the provenance area has favorable weathering and denudation conditions; and an aluminum-gallium formation under strong leaching is contained within. (3) Delineation of lithium metallogenic zones in coal requires: relatively clear sources of lithium in the zones; favorable weathering and denudation conditions in the provenance area; and aluminum-lithium containing rocks under strong leaching. (4) Delineation of rare earth mineralization zones in coal is based on: large scale volcanic eruptions in or near peat bogs during the accumulation period, with tuff in the coal-bearing strata; and hydrothermal intrusion into coal-measure strata during the peat bog period or early coal-forming period. According to the principles above, seven coal-metal metallogenic zones were identified, including: (1) the Erlian Basin-Hailaer Basin coal-germanium and REE deposit zone; (2) the Tianshan coal-gallium deposit zone; (3) the South-Yinshan coal-gallium-lithium deposit zone; (4) the East-Taihang Mountain coal-gallium deposit zone; (5) the Qilian-Qinling coal-gallium-lithium deposit zone; (6) the Sichuan-Yunnan-Guangxi coal-gallium-lithium and REE deposit zone; and (7) the Sanjiang (west Yunnan Province) germanium deposit zone.

An isotopic perspective on the socio-economic significance of livestock in Bronze Age West-Frisia, the Netherlands (2000–800 BCE)

The Bronze Age is increasingly characterised as a period in which the search for and trade in metals dominates mobility and exchange in Europe. Chiefs travelled the lands and seas and dominated the acquisition and possession of critical resources. Most research focuses on the provenance and distribution of metals and on the mobility of people. Yet, the mobility of one the most obvious sources of social and economic wealth in the Bronze Age has got little attention: livestock. This study explores the possible social role of livestock of cattle and sheep, both in the household sphere and in the sphere of exchange as a means of ‘connecting people’. Here, strontium isotope data are presented from 58 cattle and sheep from settlement contexts from Bronze Age West-Frisia (2000–800 BCE), the Netherlands, with the aim to gain an isotopic perspective on the socio-economic significance of livestock. The data provide evidence for long-distance trade or exchange of livestock. Besides their monetary value, we suggest that livestock, and in particular cattle, may have been perceived as equal to people in terms of labour and production and as members of the household. Their mobility and exchange therefore signal more than just economic trade, it signals a social practice. By changing our perspective towards the social ideology of farming life, we will move closer to understanding Bronze Age societies in more diverse and inclusive ways. Research into livestock mobility is therefore considered fundamental for a more diverse understanding of Bronze Age farming life.

Spatial variability and determinants of atmospheric methane concentrations in the metropolitan city of Shanghai, China

Methane, CH4, is a powerful greenhouse gas released to the atmosphere by both anthropogenic and natural sources. Urban areas play an important role in greenhouse gas emissions, yet few efforts have been made to investigate CH4 concentration and its spatial variability in cities. In this paper, a case study to monitor the spatial pattern and determinants of near-surface urban CH4 concentration was conducted in Shanghai, the commercial and financial center of mainland China. A total of 173 sampling points were collected to examine the atmospheric CH4 concentration across different land use types and urban-rural gradients at a height of 2 m above the ground in April and May 2014. The contributions of potential influencing factors, including four indicators of human activities (e.g., distance to natural gas pipelines [Dist_gas], distance to sewage plants [Dist_sew], population density [Den_pop], density of road network [Den_road]) and two indicators of natural conditions (i.e., planetary boundary layer height [BLH] and land surface temperature [LST]), in determining spatial CH4 concentrations were investigated using Lindeman-Merenda-Gold (LMG) metric. The results indicated that the average CH4 concentration in the morning for the region was 1,897 ± 92 parts per billion by volume (ppbv), with significant spatial heterogeneity. Atmospheric CH4 had negative correlation with the distance to urban center except the influence of obvious emission sources, such as petrochemical plants etc. The six selected influencing factors could explain 76.3% of the CH4 spatial variability. Population density was the dominant factor for about 27.2%, while the distance to the natural gas pipelines, planetary boundary layer height and distance to the sewage plants were about 14.4%, 14.2% and 12.6%, respectively. The finding in this study might help to build a better understanding of the mechanics of CH4 variations and evaluation of the potentially influencing factors.

Effect of Different Hole-Making Technology on Fatigue Properties of Directionally Solidified Alloy IC10

The fatigue tests were carried out under two kinds of hole-making technology, forming EDM and high-speed EDM. The hole taper and fracture surface of the sample were compared and analyzed. The finite element model with hole taper was established and the influence of the hole making technology on fatigue life was analyzed. Three conclusions have been obtained:First, the inner surface of the hole of the formed EDM is relatively flat, the residual deposit formed during the processing is less. and thickness of the recast layer and the content of oxygen are also lower than the high-speed EDM. Second,The fracture surface of the formed EDM shows obvious crack source, while the high-speed EDM has no crack source, and the area of the crack propagation area of the high-speed EDM is obviously larger. Third,the high-speed electric spark machining has obvious taper, under the load condition, the stress at the large hole end is higher than that at the small hole end, and large strain and damage are generated at the same time, resulting in crack initiation at the end of the large hole.

ACTIVATED SLUDGE PROCESS OF WASTEWATER TREATMENT PLANT

يمكن وصف مياه الصرف على أنها مياه تم استخدامها لنقل الملوثات بعيدًا عن مصدر التلوث. ينشأ في المنازل والشركات والمدارس والمستشفيات والسجون والصناعات ، وفي النهاية يتم تصريفه مرة أخرى في البيئة. توجد المواد الصلبة في كل مياه الصرف تقريبًا ، وقد تكون ضارة جدًا بالبيئة ، وبالتالي يتم تنظيمها في كثير من الأحيان في تصريف مياه الصرف الصحي. كان الهدف من هذه الدراسة هو نية استخدام التحكم في عملية الحمأة المنشطة وتشغيل عملية الحمأة المنشطة ، بما في ذلك إزالة المغذيات ، واستكشاف الأخطاء وإصلاحها. تم الاتصال بهذه الدراسة مع محطات الصرف الصحي في المملكة العربية السعودية كدليل إرشادي للصيانة واستكشاف الأخطاء وإصلاحها. عند استكشاف مشاكل الحمأة المنشطة ، تم التغاضي عن المصادر والحلول الواضحة لصالح الغريب وغير المعتاد.

Hepatitis A—2017 an unusual year in Scotland

BackgroundThe number of cases of acute hepatitis A reported in Scotland each year is small, and the majority of cases have been associated with travel to endemic regions. However, in early 2017, in the midst of ongoing outbreaks of hepatitis A among MSM in Europe, there was a sharp rise in the number of cases reported to Health Protection Scotland. ObjectivesThe initial aim of this study was to investigate the reason for the observed increase in cases of hepatitis A at the start of 2017. As cases continued for the remainder of the year, these cases were typed to determine whether these cases were linked to each other, or other outbreaks. Study designThe study population consisted of 42 hepatitis A infected patients with no obvious source of infection. The patient samples were collected between January and December 2017. The VP1/2 A region was amplified and sequenced. ResultsThe majority of samples typed as genotype 1 A (n = 17) or genotype 1B (n = 15). Within genotype 1 A, fifteen samples had strains (VRD_521_2016 or RIVM_HAV16_090) associated with ongoing outbreaks of hepatitis A in MSM in Europe. Within genotype 1B, there were four clusters of infections, with identical cases in geographically distinct regions with no identified epidemiological link. ConclusionsMolecular typing proved useful, as it allowed public health to identify clusters, establish links with other outbreaks and compare Scottish strains with those reported elsewhere.