scholarly journals Ore-Forming Fluid Evolution in the Giant Gejiu Sn–Cu Polymetallic Ore Field, SW China: Evidence From Fluid Inclusions

2021 ◽  
Vol 9 ◽  
Author(s):  
Yongqing Chen ◽  
Zhenyi Wang ◽  
Jiande Li
Keyword(s):  
Low Temperature ◽  
Fluid Inclusions ◽  
Stage Iv ◽  
Ore Deposits ◽  
Stage I ◽  
Critical Conditions ◽  
Laser Raman Spectra ◽  
Granitic Intrusion ◽  
Different Types ◽  
Polymetallic Ore

The giant Gejiu Sn–Cu polymetallic ore deposit is one of the largest Sn producers in the world, and is related in time and space to highly evolved S type granitic intrusion. The mineralization processes can be divided into four stages: (I) skarnization; (II) greisenization; (III) cassiterite–sulfid; and (IV) cassiterite–tourmaline–quartz. Five types of fluid inclusions were recognized using optical petrography, microthermometry, and Raman spectroscopy. The results of microthermometry revealed the evolution of the ore-forming fluid, from a high temperature with low–to–high salinity to a low temperature with low–to–intermediate salinity. Stage I, skarn Sn–Cu ores were formed by bimetasomatism between the granitic intrusion and the surrounding rock under near–critical conditions with the help of ore-forming fluid. Stage II, the fluid was separated into the coexisting liquid and vapor phases in equilibrium condition, and a large amount of cassiterite–scheelite–beryl–lithium muscovite minerals were formed during greisenization. Stage III, mixing, boiling and immiscibility of different types of fluid solutions took place with a decline in temperature and pressure as well as a change in the Eh–pH, which caused amounts of cassiterites and sulfides to precipitate. Stage IV, stockwork ores characterized by cassiterite–tourmaline–quartz minerals were formed associated with the low temperature and low salinity hydrothermal liqiud activity. The laser Raman spectra identified CH4 in all ore-forming stages, indicating that the ore deposits might have been formed in a relatively reduced environment. CO2 appeared in all stages in addition to Stage I, and might have been formed due to both immiscibility of fluid solutions with dropping pressure as well as temperature and mixing of different types of fluid solutions. In conclusion, the bimetasomatism, mixing, and immiscibility of fluid solutions should have been responsible for the formation of giant Sn–Cu polymetallic deposits.

scholarly journals Fluid Evolution and Ore Genesis of the Qibaoshan Polymetallic Ore Field, Shandong Province, China: Constraints from Fluid Inclusions and H–O–S Isotopic Compositions

Minerals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 394
Author(s):  
Yu ◽  
Li ◽  
Wang ◽  
Wang
Keyword(s):  
Fluid Inclusion ◽  
Fluid Inclusions ◽  
Meteoric Water ◽  
Ore Deposits ◽  
Shandong Province ◽  
Isotopic Data ◽  
Magmatic Water ◽  
Oxygen Isotopic ◽  
Stage 1 ◽  
Polymetallic Ore

The Qibaoshan polymetallic ore field is located in the Wulian area, Shandong Province, China. Four ore deposits occur in this ore field: the Jinxiantou Au–Cu, Changgou Cu–Pb–Zn, Xingshanyu Pb–Zn, and Hongshigang Pb–Zn deposits. In the Jinxiantou deposit, three paragenetic stages were identified: quartz–pyrite–specularite–gold (Stage 1), quartz–pyrite–chalcopyrite (Stage 2), and quartz–calcite–pyrite (Stage 3). Liquid-rich aqueous (LV type), vapor-rich aqueous (V type), and halite-bearing (S type) fluid inclusions (FIs) are present in the quartz from stages 1–3. Microthermometry indicates that the initial ore-forming fluids had temperatures of 351–397 °C and salinities of 42.9–45.8 mas. % NaCl equivalent. The measured hydrogen and calculated oxygen isotopic data for fluid inclusion water (δ18OFI = 11.1 to 12.3‰; δDFI = −106.3 to −88.6‰) indicates that the ore-forming fluids were derived from magmatic water; then, they were mixed with meteoric water. In the Changgou deposit, three paragenetic stages were identified: quartz–pyrite–specularite (Stage 1), quartz–pyrite–chalcopyrite (Stage 2), and quartz–galena–sphalerite (Stage 3). LV, V, and S-type FIs are present in the quartz from stages 1–3. Microthermometry indicates that the initial ore-forming fluids had temperatures of 286–328 °C and salinities of 36.7–40.2 mas. % NaCl equivalent. The measured hydrogen and calculated oxygen isotopic data for fluid inclusion water (δDFI = −115.6 to −101.2‰; δ18OFI = 12.2 to 13.4‰) indicates that the ore-forming fluids were derived from magmatic water mixed with meteoric water. The characteristics of the Xingshanyu and Hongshigang deposits are similar. Two paragenetic stages were identified in these two deposits: quartz–galena–sphalerite (Stage 1) and quartz–calcite–poor sulfide (Stage 2). Only LV-type FIs are present in the quartz in stages 1–2. The ore-forming fluids had temperatures of 155–289 °C and salinities of 5.6–10.5 mas. % NaCl equivalent. The measured hydrogen and calculated oxygen isotopic data for fluid inclusion water (δDFI = −109.8 to −100.2‰; δ18OFI = 10.2 to 12.1‰) indicates that the ore-forming fluids were derived from circulating meteoric waters. The sulfur isotopes (δ34Ssulfide = 0.6 to 4.3‰) of the four deposits are similar, indicating a magmatic source for the sulfur with minor contributions from the wall rocks. The ore field underwent at least two phases of mineralization according to the chronology results of previous studies. Based on the mineral assemblage and fluid characteristics, we suggest that the late Pb–Zn mineralization was superimposed on the early Cu (–Au) mineralizaton in the Changgou deposit.

scholarly journals Ore Genesis of Shanmen Ag Deposit in Siping Area of Southern Jilin Province, NE China: Constraints from Fluid Inclusions and H-O, S, Pb Isotopes

Minerals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 586 ◽  
Author(s):  
Sun ◽  
Ren ◽  
Cao ◽  
Hao ◽  
Gao
Keyword(s):  
Low Temperature ◽  
Fluid Inclusions ◽  
Stage I ◽  
Ne China ◽  
Two Phase ◽  
Low Salinity ◽  
Temperature Environment ◽  
Homogenization Temperatures ◽  
Late Stages ◽  
Stage Stage

The Shanmen Ag deposit, located in the southeastern part of the Siping area, Jilin Province, is one of the large-scale Ag deposits in Northeastern (NE) China. Almost all Ag orebodies, Ag-bearing quartz-sulfide veins are strictly controlled by NE-trending faults or brittle fractures and are hosted in the Yanshanian monzonite and quartz diorite. In terms of deposit geology, three mineralization stages are recognized: the pyrite-quartz stage (I), the quartz-Ag-polymetallic sulfide stage (II), and the carbonate-quartz stage (III). The research results of the fluid inclusions in the different stages indicate that the early stage (Stage I) mainly contains three types of fluid inclusions: liquid-rich two-phase (L-type), vapor-rich two-phase (V-type), and CO2 aqueous multi-phase (C-type). The fluid belongs to a medium–high temperature and medium–low salinity H2O-NaCl-CO2 system and has boiling characteristics. The middle stage (Stage II) is mainly characterized by liquid-rich two-phase (L-type) and vapor-rich two-phase (V-type) inclusions, in which the mixing of fluids of different nature leads to the escape of CO2. Only liquid-rich two-phase (L-type) inclusions are distinguished in the late stage (Stage III). The fluids of two later stages belong to the medium-low-temperature and low-salinity H2O-NaCl system. Homogenization temperatures from the early to late stages range from 272.2 to 412.5 °C, 124.1 to 313.3 °C, and 128.6 to 224 °C, respectively. Fluid salinities in the early to late stages range from 1.6 to 12.1, 1.4 to 8.9, and 0.4 to 5.8 wt.% NaCl equivalent, respectively. The gradually decreasing trends of homogenization temperatures and salinities and the reduction in the CO2 content indicate that the release of CO2 and the low-temperature environment are important causes of the precipitation of Ag-bearing minerals. The δ18OH2O values of the ore-bearing quartz veins in the different stages range from −3.7 to +8.1‰, and the δD values of fluid inclusions in the quartz range from −113 to −103‰, indicating that the initial ore-forming fluid was mainly derived from magma and that the input of meteoric water gradually increased during the mineralization process. The δ34S values (ranging from −11.4‰ to +1.8‰) and Pb isotope compositions (206Pb/204Pb = 18.143–18.189, 207Pb/204Pb = 15.543–15.599, 208Pb/204Pb = 38.062–38.251) of sulfides suggest that the ore-forming materials have mixed mantle and crustal sources. Therefore, we propose that the release of CO2 and the low-temperature environment are important conditions for silver minerals precipitation, and the mixing of fluids of different nature is the dominant mechanism causing precipitation. The Shanmen Ag deposit can be classified as an intrusion-related medium–low temperature hydrothermal vein-type deposit.

scholarly journals GERMINATION AND VIGOUR IN SEEDS OF THE COWPEA IN RESPONSE TO SALT AND HEAT STRESS

2019 ◽  
Vol 32 (1) ◽  
pp. 143-151 ◽  
Author(s):  
Luma Rayane de Lima Nunes ◽  
Paloma Rayane Pinheiro ◽  
Charles Lobo Pinheiro ◽  
Kelly Andressa Peres Lima ◽  
Alek Sandro Dutra
Keyword(s):  
Salt Stress ◽  
Heat Stress ◽  
High Temperature ◽  
Low Temperature ◽  
Vigna Unguiculata ◽  
Salt Concentration ◽  
Dry Weight ◽  
Germination Percentage ◽  
Different Types ◽  
Different Temperatures

ABSTRACT Salinity is prejudicial to plant development, causing different types of damage to species, or even between genotypes of the same species, with the effects being aggravated when combined with other types of stress, such as heat stress. The aim of this study was to evaluate the tolerance of cowpea genotypes (Vigna unguiculata L. Walp.) to salt stress at different temperatures. Seeds of the Pujante, Epace 10 and Marataoã genotypes were placed on paper rolls (Germitest®) moistened with different salt concentrations of 0.0 (control), 1.5, 3.0, 4.5 and 6.0 dS m-1, and placed in a germination chamber (BOD) at temperatures of 20, 25, 30 and 35°C. The experiment was conducted in a completely randomised design, in a 3 × 4 × 5 scheme of subdivided plots, with four replications per treatment. The variables under analysis were germination percentage, first germination count, shoot and root length, and total seedling dry weight. At temperatures of 30 and 35°C, increases in the salt concentration were more damaging to germination in the Epace 10 and Pujante genotypes, while for the Marataoã genotype, damage occurred at the temperature of 20°C. At 25°C, germination and vigour in the genotypes were higher, with the Pujante genotype proving to be more tolerant to salt stress, whereas Epace 10 and Marataoã were more tolerant to high temperatures. Germination in the cowpea genotypes was more sensitive to salt stress when subjected to heat stress caused by the low temperature of 20°C or high temperature of 35°C.

The Pilot Knob Iron Ore Deposits in Southeast Missouri: A High-To-Low Temperature Magmatic-Hydrothermal Continuum

2021 ◽  
pp. 103973
Author(s):  
Bolorchimeg N. Tunnell ◽  
Marek Locmelis ◽  
Cheryl Seeger ◽  
Ryan Mathur ◽  
István Dunkl ◽  
...  
Keyword(s):  
Low Temperature ◽  
Iron Ore ◽  
Ore Deposits ◽  
Southeast Missouri ◽  
Iron Ore Deposits

scholarly journals Gastric Cancer Treatments and Survival Trends in the United States

2020 ◽  
Vol 28 (1) ◽  
pp. 138-151
Author(s):  
Kelly A. Stahl ◽  
Elizabeth J. Olecki ◽  
Matthew E. Dixon ◽  
June S. Peng ◽  
Madeline B. Torres ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Overall Survival ◽  
Stage Iv ◽  
The United States ◽  
Current Treatment ◽  
Stage I ◽  
Stage Ii ◽  
Chi Square ◽  
Specific Guideline ◽  
Kaplan Meier

Gastric cancer is the third most common cause of cancer deaths worldwide. Despite evidence-based recommendation for treatment, the current treatment patterns for all stages of gastric cancer remain largely unexplored. This study investigates trends in the treatments and survival of gastric cancer. The National Cancer Database was used to identify gastric adenocarcinoma patients from 2004–2016. Chi-square tests were used to examine subgroup differences between disease stages: Stage I, II/III and IV. Multivariate analyses identified factors associated with the receipt of guideline concordant care. The Kaplan–Meier method was used to assess three-year overall survival. The final cohort included 108,150 patients: 23,584 Stage I, 40,216 Stage II/III, and 44,350 Stage IV. Stage specific guideline concordant care was received in only 73% of patients with Stage I disease and 51% of patients with Stage II/III disease. Patients who received guideline consistent care had significantly improved survival compared to those who did not. Overall, we found only moderate improvement in guideline adherence and three-year overall survival during the 13-year study time period. This study showed underutilization of stage specific guideline concordant care for stage I and II/III disease.

scholarly journals Serum Biomarker Signature-Based Liquid Biopsy for Diagnosis of Early-Stage Pancreatic Cancer

2018 ◽  
Vol 36 (28) ◽  
pp. 2887-2894 ◽  
Author(s):  
Linda D. Mellby ◽  
Andreas P. Nyberg ◽  
Julia S. Johansen ◽  
Christer Wingren ◽  
Børge G. Nordestgaard ◽  
...  
Keyword(s):  
Case Control Study ◽  
Early Stage ◽  
Stage Iv ◽  
The United States ◽  
Case Control ◽  
Stage I ◽  
Serum Biomarker ◽  
Patient Cohort ◽  
Biomarker Signature ◽  
Control Study

Purpose Pancreatic ductal adenocarcinoma (PDAC) has a poor prognosis, with a 5-year survival of < 10% because of diffuse symptoms leading to late-stage diagnosis. That survival could increase significantly if localized tumors could be detected early. Therefore, we used multiparametric analysis of blood samples to obtain a novel biomarker signature of early-stage PDAC. The signature was derived from a large patient cohort, including patients with well-defined early-stage (I and II) PDAC. This biomarker signature was validated subsequently in an independent patient cohort. Patients and Methods The biomarker signature was derived from a case-control study, using a Scandinavian cohort, consisting of 16 patients with stage I, 132 patients with stage II, 65 patients with stage III, and 230 patients with stage IV PDAC, and 888 controls. This signature was validated subsequently in an independent case-control cohort in the United States with 15 patients with stage I, 75 patients with stage II, 15 patients with stage III, and 38 patients with stage IV PDAC, and 219 controls. An antibody microarray platform was used to identify the serum biomarker signature associated with early-stage PDAC. Results Using the Scandinavian case-control study, a biomarker signature was created, discriminating samples derived from patients with stage I and II from those from controls with a receiver operating characteristic area under the curve value of 0.96. This signature, consisting of 29 biomarkers, was then validated in an independent case-control study in the United States. The biomarker signature could discriminate patients with stage I and II PDAC from controls in this independent patient cohort with a receiver operating characteristic area under the curve value of 0.96. Conclusion This serum biomarker signature might represent a tenable approach to detecting early-stage, localized PDAC if these findings are supported by a prospective validation study.

XMAP230 is required for the assembly and organization of acetylated microtubules and spindles in Xenopus oocytes and eggs

1998 ◽  
Vol 111 (16) ◽  
pp. 2315-2327 ◽  
Author(s):  
B.J. Cha ◽  
B. Error ◽  
D.L. Gard
Keyword(s):  
Late Stage ◽  
Xenopus Oocytes ◽  
Early Stage ◽  
Polyclonal Antibodies ◽  
Stage Iv ◽  
Stage I ◽  
Meiotic Spindle ◽  
Heat Stable ◽  
Early Embryos ◽  
And Function

We used affinity-purified polyclonal antibodies to characterize the distribution and function of XMAP230, a heat-stable microtubule-associated protein isolated from Xenopus eggs, during oogenesis. Immunoblots revealed that XMAP230 was present throughout oogenesis and early development, but was most abundant in late stage oocytes, eggs, and early embryos. Immunofluorescence microscopy revealed that XMAP230 was associated with microtubules in oogonia, post-mitotic stage 0 oocytes, early stage I oocytes, and during stage IV-VI of oogenesis. However, staining of microtubules by anti-XMAP230 was not detectable during late stage I through stage III. In stage VI oocytes, anti-XMAP230 stained a large subset of microtubules that were also stained with monoclonal antibodies specific for acetylated (α)-tubulin. During oocyte maturation, XMAP230 was associated with the transient microtubule array that serves as the precursor of the first meiotic spindle, as well as both first and second meiotic spindles. The extensive array of cytoplasmic microtubules present throughout maturation was not detectably stained by anti-XMAP230. Microinjection of anti-XMAP230 locally disrupted the organization and acetylation of microtubules in stage VI oocytes, and reduced the re-acetylation of microtubules during recovery from cold-induced microtubule disassembly. Subsequent maturation of oocytes injected with anti-XMAP230 resulted in defects in the assembly of the transient microtubules array and first meiotic spindle. These observations suggest that XMAP230 is required for the stabilization and organization of cytoplasmic and spindle microtubules in Xenopus oocytes and eggs.

The impact of the COVID-19 pandemic on stage at diagnosis of breast and colorectal cancers.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 6501-6501
Author(s):  
Jade Zhou ◽  
Shelly Kane ◽  
Celia Ramsey ◽  
Melody Ann Akhondzadeh ◽  
Ananya Banerjee ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Colorectal Cancer ◽  
Cancer Screening ◽  
Late Stage ◽  
Stage Iv ◽  
Stage I ◽  
Screening Programs ◽  
Stage Distribution ◽  
Number Of Patients ◽  
The Impact

6501 Background: Effective cancer screening leads to a substantial increase in the detection of earlier stages of cancer, while decreasing the incidence of later stage cancer diagnoses. Timely screening programs are critical in reducing cancer-related mortality in both breast and colorectal cancer by detecting tumors at an early, curable stage. The COVID-19 pandemic resulted in the postponement or cancellation of many screening procedures, due to both patient fears of exposures within the healthcare system as well as the cancellation of some elective procedures. We sought to identify how the COVID-19 pandemic has impacted the incidence of early and late stage breast and colorectal cancer diagnoses at our institution. Methods: We examined staging for all patients presenting to UCSD at first presentation for a new diagnosis of malignancy or second opinion in 2019 and 2020. Treating clinicians determined the stage at presentation for all patients using an AJCC staging module (8th edition) in the electronic medical record (Epic). We compared stage distribution at presentation in 2019 vs 2020, both for cancers overall and for colorectal and breast cancer, because these cancers are frequently detected by screening. Results: Total numbers of new patient visits for malignancy were similar in 2019 and 2020 (1894 vs 1915 pts), and stage distribution for all cancer patients was similar (stage I 32% in 2019 vs 29% in 2020; stage IV 26% in both 2019 and 2020). For patients with breast cancer, we saw a lower number of patients presenting with stage I disease (64% in 2019 vs 51% in 2020) and a higher number presenting with stage IV (2% vs 6%). Similar findings were seen in colorectal cancer (stage I: 22% vs 16%; stage IV: 6% vs 18%). Conclusions: Since the COVID-19 pandemic, there has been an increase in incidence of late stage presentation of colorectal and breast cancer, corresponding with a decrease in early stage presentation of these cancers at our institution. Cancer screening is integral to cancer prevention and control, specifically in colorectal and breast cancers which are often detected by screening, and the disruption of screening services has had a significant impact on our patients. We plan to continue following these numbers closely, and will present data from the first half of 2021 as it becomes available.

Stage at cancer diagnosis during the COVID-19 pandemic in western Washington state.

2021 ◽  
Vol 39 (28_suppl) ◽  
pp. 145-145
Author(s):  
Catherine R. Fedorenko ◽  
Karma L. Kreizenbeck ◽  
Li Li ◽  
Laura Elizabeth Panattoni ◽  
Veena Shankaran ◽  
...  
Keyword(s):  
Medical Care ◽  
Early Stage ◽  
Stage Iv ◽  
Washington State ◽  
Stage I ◽  
Tumor Type ◽  
Stage At Diagnosis ◽  
Stage Iv Cancer ◽  
Using Data ◽  
The Impact

145 Background: The COVID-19 pandemic disrupted medical care, including routine cancer screening for breast, colorectal, lung and cervical cancers. We aimed to investigate the impact of the pandemic on stage at diagnosis for cancer patients. Methods: Using data from the Washington State SEER records we compared AJCC stage for patients diagnosed with cancer in 2017-2019 to 2020 for two time periods, March to June (initial pandemic months) and July to December (later pandemic months). Patients were included if they were age 18+, diagnosed with a solid tumor, and not diagnosed at autopsy. Results: In the early phase of the pandemic, March – June 2020, there was a shift to cancers being diagnosed at a later stage compared to the same time period in 2017-2019 (Stage III: 13.5% to 14.9%, Stage IV: 16.2% to 19.7%). There was also a decrease in cancer diagnoses for cancers that are often detected through routine screening. As a percentage of all cancer diagnoses, both melanoma (13.2% to 9.8%) and colon cancer diagnoses (7.2% to. 6.7%) decreased during the early pandemic. In the later phase of the pandemic, July to December 2020, the stage at diagnosis showed an indication of returning to pre-pandemic levels with an increase in the proportion of early stage cancers (In situ: 16.6% to 19.3%, Stage I: 38.8% to 41.1%). Stage at diagnosis trends varied by tumor type. For colorectal cancer, the overall number of diagnoses decreased during the initial pandemic months. Stage I diagnoses decreased and Stage IV cancer diagnoses increased in both early and late stages of the pandemic. Conclusions: In Washington State, the COVID-19 pandemic had an impact on stage at diagnosis potentially caused by delays or interruptions in medical care. Additional studies are needed to understand how this shift in stage at diagnosis impacted treatment and outcomes for patients.

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