scholarly journals Origin and Evolution of Ore-Forming Fluid and Gold-Deposition Processes at the Sanshandao Gold Deposit, Jiaodong Peninsula, Eastern China

Minerals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 189 ◽  
Author(s):  
Yazhou Liu ◽  
Liqiang Yang ◽  
Sirui Wang ◽  
Xiangdong Liu ◽  
Hao Wang ◽  
...  
Keyword(s):  
Fluid Inclusion ◽  
Gold Deposit ◽  
Early Stage ◽  
Gold Deposition ◽  
Main Stage ◽  
Type Ii ◽  
Type Iii ◽  
Stage 4 ◽  
Stage 1 ◽  
Stage Stage

The Early Cretaceous Sanshandao gold deposit, the largest deposit in the Sanshandao-Cangshang goldfield, is located in the northwestern part of the Jiaodong peninsula. It is host to Mesozoic granitoids and is controlled by the north by northeast (NNE) to northeast (NE)-trending Sanshandao-Cangshang fault. Two gold mineralizations were identified in the deposit’s disseminated and stockwork veinlets and quartz–sulfide veins, which are typically enveloped by broad alteration selvages. Based on the cross-cutting relationships and mineralogical and textural characteristics, four stages have been identified for both styles of mineralization: Pyrite–quartz (stage 1), quartz–pyrite (stage 2), quartz–pyrite–base metal–sulfide (stage 3), and quartz–carbonate (stage 4), with gold mainly occurring in stages 2 and 3. Three types of fluid inclusion have been distinguished on the basis of fluid-inclusion assemblages in quartz and calcite from the four stages: Pure CO2 gas (type I), CO2–H2O inclusions (type II), and aqueous inclusions (type III). Early-stage (stage 1) quartz primary inclusions are only type II inclusions, with trapping at 280–400 °C and salinity at 0.35 wt %–10.4 wt % NaCl equivalent. The main mineralizing stages (stages 2 and 3) typically contain primary fluid-inclusion assemblages of all three types, which show similar phase transition temperatures and are trapped between 210 and 320 °C. The late stage (stage 4) quartz and calcite contain only type III aqueous inclusions with trapping temperatures of 150–230 °C. The δ34S values of the hydrothermal sulfides from the main stage range from 7.7‰ to 12.6‰ with an average of 10.15‰. The δ18O values of hydrothermal quartz mainly occur between 9.7‰ and 15.1‰ (mainly 10.7‰–12.5‰, average 12.4‰); calculated fluid δ18O values are from 0.97‰ to 10.79‰ with a median value of 5.5‰. The δDwater values calculated from hydrothermal sericite range from −67‰ to −48‰. Considering the fluid-inclusion compositions, δ18O and δD compositions of ore-forming fluids, and regional geological events, the most likely ultimate potential fluid and metal would have originated from dehydration and desulfidation of the subducting paleo-Pacific slab and the subsequent devolatilization of the enriched mantle wedge. Fluid immiscibility occurred during the main ore-forming stage due to pressure decrease from the early stage (165–200 MPa) to the main stage (90–175 MPa). Followed by the changing physical and chemical conditions, the metallic elements (including Au) in the fluid could no longer exist in the form of complexes and precipitated from the fluid. Water–rock sulfidation and pressure fluctuations, with associated fluid unmixing and other chemical changes, were the two main mechanisms of gold deposition.

scholarly journals Ore-Fluid Evolution of the Sizhuang Orogenic Gold Deposit, Jiaodong Peninsula, China

Minerals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 190 ◽  
Author(s):  
Yu-Ji Wei ◽  
Li-Qiang Yang ◽  
Jian-Qiu Feng ◽  
Hao Wang ◽  
Guang-Yao Lv ◽  
...  
Keyword(s):  
Fluid Inclusion ◽  
Gold Deposit ◽  
Late Stage ◽  
Gold Mineralization ◽  
Early Stage ◽  
Main Stage ◽  
Jiaodong Peninsula ◽  
Wide Range ◽  
Homogenization Temperatures

The Sizhuang gold deposit with a proven gold resource of >120 t, located in northwest Jiaodong Peninsula in China, lies in the southern part of the Jiaojia gold belt. Gold mineralization can be divided into altered rock type, auriferous quartz vein type, and sulfide-quartz veinlet in K-feldspar altered granite. According to mineral paragenesis and mineral crosscutting relationships, three stages of metal mineralization can be identified: early stage, main stage, and late stage. Gold mainly occurs in the main stage. The petrography and microthermometry of fluid inclusion shows three types of inclusions (type 1 H2O–CO2 inclusions, type 2 aqueous inclusions, and type 3 CO2 inclusions). Early stage quartz-hosted inclusions have a trapped temperatures range 303–390 °C. The gold-rich main stage contains a fluid-inclusion cluster with both type 1 and 2 inclusions (trapped between 279 and 298 °C), and a wide range of homogenization temperatures of CO2 occurs to the vapor phase (17.6 to 30.5 °C). The late stage calcite only contains type 1 inclusions with homogenization temperatures between 195 and 289 °C. With evidences from the H–O isotope data and the study of water–rock interaction, the metamorphic water of the Jiaodong Group is considered to be the dominating source for the ore-forming fluid. The ore-fluid belonged to a CO2–H2O–NaCl system with medium-low temperature (160–360 °C), medium-low salinity (3.00–11.83 wt% NaCl eq.), and low density (1.51–1.02 g/cm3). Fluid immiscibility caused by pressure fluctuation is the key mechanism in inducing gold mineralization in the Sizhuang gold deposit.

Alterations in the number of motoneurons containing immunoreactive calcitonin gene-related peptide(CGRP)& choline acetyltransferase(ChAT) in the cervical spinal cord of the wobbler mouse during the development of the motoneuron disease

1995 ◽  
Vol 53 ◽  
pp. 970-971
Author(s):  
L. Vacca-Galloway ◽  
Y.Q. Zhang ◽  
P. Bose ◽  
S.H. Zhang
Keyword(s):  
Spinal Cord ◽  
Early Stage ◽  
Cervical Spinal Cord ◽  
Wild Type Mouse ◽  
Reflex Response ◽  
Mouse Strains ◽  
Behavioral Tests ◽  
Wobbler Mouse ◽  
Stage 4 ◽  
Stage 1

The Wobbler mouse (wr) has been studied as a model for inherited human motoneuron diseases (MNDs). Using behavioral tests for forelimb power, walking, climbing, and the “clasp-like reflex” response, the progress of the MND can be categorized into early (Stage 1, age 21 days) and late (Stage 4, age 3 months) stages. Age-and sex-matched normal phenotype littermates (NFR/wr) were used as controls (Stage 0), as well as mice from two related wild-type mouse strains: NFR/N and a C57BI/6N. Using behavioral tests, we also detected pre-symptomatic Wobblers at postnatal ages 7 and 14 days. The mice were anesthetized and perfusion-fixed for immunocytochemical (ICC) of CGRP and ChAT in the spinal cord (C3 to C5).Using computerized morphomety (Vidas, Zeiss), the numbers of IR-CGRP labelled motoneurons were significantly lower in 14 day old Wobbler specimens compared with the controls (Fig. 1). The same trend was observed at 21 days (Stage 1) and 3 months (Stage 4). The IR-CGRP-containing motoneurons in the Wobbler specimens declined progressively with age.

scholarly journals Temporal changes of quantitative CT findings from 102 patients with COVID-19 in Wuhan, China: A longitudinal study

2021 ◽  
Vol 29 ◽  
pp. 297-309
Author(s):  
Xiaohui Chen ◽  
Wenbo Sun ◽  
Dan Xu ◽  
Jiaojiao Ma ◽  
Feng Xiao ◽  
...  
Keyword(s):  
Lung Diseases ◽  
Early Stage ◽  
Temporal Changes ◽  
Time Interval ◽  
Lesion Area ◽  
Quantitative Ct ◽  
Diagnosis And Prognosis ◽  
Ct Findings ◽  
Stage 4 ◽  
Stage 1

BACKGROUND: Computed tomography (CT) imaging combined with artificial intelligence is important in the diagnosis and prognosis of lung diseases. OBJECTIVE: This study aimed to investigate temporal changes of quantitative CT findings in patients with COVID-19 in three clinic types, including moderate, severe, and non-survivors, and to predict severe cases in the early stage from the results. METHODS: One hundred and two patients with confirmed COVID-19 were included in this study. Based on the time interval between onset of symptoms and the CT scan, four stages were defined in this study: Stage-1 (0 ∼7 days); Stage-2 (8 ∼ 14 days); Stage-3 (15 ∼ 21days); Stage-4 (> 21 days). Eight parameters, the infection volume and percentage of the whole lung in four different Hounsfield (HU) ranges, ((-, -750), [-750, -300), [-300, 50) and [50, +)), were calculated and compared between different groups. RESULTS: The infection volume and percentage of four HU ranges peaked in Stage-2. The highest proportion of HU [-750, 50) was found in the infected regions in non-survivors among three groups. CONCLUSIONS: The findings indicate rapid deterioration in the first week since the onset of symptoms in non-survivors. Higher proportion of HU [-750, 50) in the lesion area might be a potential bio-marker for poor prognosis in patients with COVID-19.

Ore geology, fluid inclusion, and stable isotope constraints on the origin of the Damoqujia gold deposit, Jiaodong Peninsula, China

2020 ◽  
Vol 57 (12) ◽  
pp. 1428-1446
Author(s):  
Peng Chai ◽  
Hong-rui Zhang ◽  
Zeng-qian Hou ◽  
Zhi-yu Zhang ◽  
Lei-lei Dong
Keyword(s):  
Fluid Inclusion ◽  
Gold Deposit ◽  
Eastern China ◽  
Homogeneous System ◽  
Gold Deposition ◽  
Medium Temperature ◽  
Rock Interaction ◽  
Jiaodong Peninsula ◽  
Primary Fluid ◽  
Gold Producer

The Damoqujia gold deposit within the Zhaoping Fault Zone on Jiaodong Peninsula in eastern China is hosted primarily by Mesozoic granitoids and contains >60 t of gold, making it an important gold producer. Three mineralization stages are distinguished (early, middle, and late): (K-feldspar)–sericite–quartz–pyrite, quartz – gold – polymetallic sulfides, and quartz–carbonate. Gold deposition occurred mainly in the middle stage. The primary fluid inclusions of three stages are mainly homogenized at temperatures of 236–389, 191–346, and 104–251 °C, with salinities of 2.96–11.33, 1.39–17.28, and 0.53–11.48 wt.% NaCl equivalent, respectively. Fluid inclusion studies indicate that the metallogenic system evolved from CO2-rich mesothermal homogeneous fluids to CO2-poor aqueous fluids due to inputs of meteoric waters. The gold was carried as a bisulfide complex in the ore-forming fluids. Precipitation of gold was caused by a combination of fluid immiscibility and water–rock interaction. Studies of the fluid inclusion characteristics (medium temperature, CO2-rich, and low salinity H2O–CO2–NaCl homogeneous system), hydrogen and oxygen isotopes ([Formula: see text] = –1.0‰ to 7.6‰, δD = –109‰ to –77‰), sulfur values ([Formula: see text] = 4.5‰ to 8.5‰), and regional geological events show that the ore-forming fluids reservoir was likely metamorphic in origin. Based on the immiscibility of fluid inclusion assemblages, the estimated depth and pressure of trapping are 8.3–10.2 km and 83–276 MPa, respectively, corresponding to the depth and pressure of mineralization.

Serum REG4 protein in pancreatic cancer as a tumor marker: A prospective study

2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 15063-15063
Author(s):  
A. Sawaki ◽  
R. Takayama ◽  
N. Mizuno ◽  
M. Tajika ◽  
N. Hoki ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Prospective Study ◽  
Early Stage ◽  
Diagnostic Sensitivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
T Stage ◽  
Stage 4 ◽  
A Prospective Study ◽  
Stage 1 ◽  
And Control

15063 Background: Pancreatic cancer (PC) shows the worst mortality rate in common malignancies, with 5-year survival rate of 4%. The only way to cure the disease is surgical resection of early stage PC. Establishment of a screening strategy to detect early stage PC is eagerly expected. REG4, a member of the regenerating islet-derived (REG) family, are secreted proteins that play a role in tissue regeneration and inflammation in digestive organs. We reported overexpression of REG4 in PC cells and serum, and preliminary data of the serum REG4 level of pancreatic disease patients including PC patients. We conducted a prospective study to evaluate the role of serum REG4 in PC. Methods: The series included 57 patients diagnosed pathologically as PC between November 2004 and December 2005. Serum REG4 was quantified by standard sandwich ELISA (Enzyme Linked Immunosorbent Assay) using original kit (MBL116: provided by Medical and Biological Laboratories Co., LTD, Japan) before treatment. The upper limit of the test was set at 3.52ng/ml and was based on studies of serum from 48 healthy control subjects. Results: With a specificity of 100%, the diagnostic sensitivity and accuracy were 63.2% and 80.0%, respectively. The ROC (receiver operating characteristic) analysis showed that area under the curve was 0.91. REG4 levels were a significant differences between PC and control (p<0.001), between each T stage and control (T1,T2, T3 or T4 v control), and between each TMN stage and control (stage 1, stage 2, stage 3 or stage 4 v control), but were not a statistical significance with T stage (T1 v T2 v T3 v T4), M stage (M0 v M1) or TNM stage (stage 1 v stage 2 v stage 3 v stage 4) in PC patients. The diagnostic sensitivity of carcinoembryonic antigen (CEA>5.0ng/ml) and carbohydrate antigen19–9 (CA19–9>50U/ml) was 56.5% and 68.4%, respectively. No significant correlation was demonstrated between REG4 and CA19–9 (coefficient of correlation [rs]=0.45). Conclusions: This study shows the potential of serum REG4 as a screening test for PC, especially for early PC. REG4 is considered to be a more useful marker in combination with CA19- 9. No significant financial relationships to disclose.

Impact of screening on presentation and survival of colorectal cancer

2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 1535-1535
Author(s):  
M. S. Beg ◽  
A. Gupta ◽  
R. Komrokji ◽  
M. Atiq ◽  
S. Ali ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Early Stage ◽  
Occult Blood ◽  
Individual Case ◽  
Fecal Occult Blood Testing ◽  
Fecal Occult Blood ◽  
Effective Population ◽  
Fecal Occult ◽  
Stage 1 ◽  
Stage Stage

1535 Background: There is an increasing emphasis and utilization of colorectal cancer (CRC) screening. We evaluated the effect of screening on CRC presentation and outcome. Methods: We reviewed all the invasive CRC cases diagnosed between Jan 1995-Dec 2005 at the Cincinnati Veteran’s Affairs hospital. Individual case records were reviewed and the data collected including patient demographics, treatment, outcome, mode of presentation as well as whether CRC was detected as a result of screening. Results: Altogether 288 patients were diagnosed with CRC during the study period. The median age at presentation was 69.3 years and 18.8% were African-Americans. Early stage CRC was diagnosed in 63.4% cases (stage 1: 32.7%, stage 2: 30.8%) and 33.3% were diagnosed at advanced stage (stage 3: 18.1% and stage 4: 15.3%). Seventy seven (26.7%) CRCs were asymptomatic at presentation and were diagnosed as a result of screening. Predominant screening modalities included fecal occult blood testing (46.8%) and flexible sigmoidoscopy (22.1%). The proportion of screen- detected cases increased from 19% in 1995–1999 to 32% in 2000–05 (p = 0.047). Demographics, including age and race, as well as the site of CRC were similar to symptomatic cases. Screen-detected cancers presented early, with 77.9% presenting at early stage (stage 1: 55.8%, stage 2: 22.1%), compared to 51.5% (stage 1: 21.0%, stage 2: 30.5%) of symptomatic cancers (p <0.01). Only 1.3% of screen-detected CRC was found to be metastatic as compared to 21.0% of the symptomatic cases. The screen-detected cancers had significant survival advantage compared to symptomatic cases; with median survival being 81 months vs. 43 months in the latter (p =0.018). A proportional hazard regression analysis indicated that this improvement in survival was related to the fact that screening resulted in earlier stage at diagnosis. Only 20.3% of screen-detected CRC received adjuvant chemotherapy compared to 41.4% of symptomatic cases (p=0.002). Conclusions: An increasing proportion of CRC is being diagnosed as a result of screening. These cancers present at an earlier stage and are associated with a significantly improved survival. However, most CRC still presents symptomatically and more effective population screening is needed. No significant financial relationships to disclose.

scholarly journals Studies on the Organizer Problem in Pelmatohydra Oligactis

1945 ◽  
Vol 21 (3-4) ◽  
pp. 155-160 ◽  
Author(s):  
H. P. LI ◽  
T. YAO
Keyword(s):  
Sudden Change ◽  
The Body ◽  
Stage I ◽  
Type I ◽  
Type Ii ◽  
Simultaneous Induction ◽  
Stage 4 ◽  
Stage 1

1. Determination of the hypostome occurs very early in the development of a bud (our stage I) in Pelmatohydra oligactis. 2. The mode of induction by a developing hypostome (type II) is different from that by an adult hypostome (type I). In the former case, an implant always induces a long tube-like outgrowth before any tentacle rudiment becomes visible. In the latter case, simultaneous induction of tentacles and body takes place. Frequently, tentacle rudiments appear before visible differentiation of the body. 3. Type II induction is characteristic of developing hypostomes from some phase of stage 1 up to a stage at which the bud possesses short, but non-motile tentacles (our stage 4). 4. As soon as the detachment of a young polyp from the parent occurs, there is a sudden change in the mode of induction, from type II to type I. 5. Possible explanations of the course of differentiation in the hypostome and of the transition between the two types of induction are suggested.

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