The fracturing of the pressure compartments in sedimentary basins may not be caused completely by natural hydraulic fracturing. On the bases of fracture mechanics and numerical simulation, we consider that there are t...The fracturing of the pressure compartments in sedimentary basins may not be caused completely by natural hydraulic fracturing. On the bases of fracture mechanics and numerical simulation, we consider that there are two mechanisms concerning the fracturing of pressure compartments, which are as follows: (1) natural hydraulic fracturing of the sediments within pressure compartments, and (2) tensile fracturing due to tangential traction. When the fracture, formed in the sediments within pressure compartments due to hydraulic fracturing, arrives at the base of the seal, the intensely tangential tensile stresses are created and lead to the fracturing of the seal. After the seal fractured, the fluid escaped from the pressure compartments. In a shallow pressure compartment, the duration of fracture opening and fluid expulsion is about 10-20 years in a cycle.展开更多
Objective:Medical expulsive therapy(MET)is a suitable option for facilitating stone expulsion in patients with distal ureteral stones.This meta-analysis was conducted to compare efficacy and safety of monotherapy and ...Objective:Medical expulsive therapy(MET)is a suitable option for facilitating stone expulsion in patients with distal ureteral stones.This meta-analysis was conducted to compare efficacy and safety of monotherapy and combination therapy with tamsulosin,silodosin,and tadalafil on stone expulsion rate(SER)and stone expulsion time(SET),as well as their comparative safety,numbers of colic pain episodes,and need for analgesics.Methods:Randomized controlled trials were retrieved by searching PubMed,Scopus,and Web of Science up to November 27,2023.Hand-searching was also conducted in Google Scholar to find additional records.Papers in English that compared the safety and efficacy of at least two of the above agents in adults with distal ureteral stones≤10 mm were included.Results:In total,27 studies were identified(six studies through database searches and 21 through checking reference lists and hand-searching in Google Scholar).More than half of them(n=15,56%)were conducted in India.The SER significantly improved with silodosin compared with tamsulosin(odds ratio[OR]2.24,p<0.001),whereas the difference in SET was non-significant.Tadalafil achieved a significantly higher SER compared with tamsulosin(OR 1.42,p=0.042)without any difference in SET.Subgroup analysis of 5-and 10-mg doses of tadalafil showed no significant difference in SER or SET.We found no significant difference in need for analgesics(mean difference(MD−53.73,p=0.2)or the mean number of colic episodes(MD−0.42,p=0.060)between tadalafil and tamsulosin.SER or SET was not significantly different between silodosin and tadalafil.Tadalafil plus tamsulosin led to a significantly higher SER(OR 1.87,p<0.001)and SET(MD−2.99,p=0.002)compared with tamsulosin,without any significant difference in adverse effects.Conclusion:Compared with tamsulosin,SER significantly improved with silodosin,tadalafil,and the combination of tadalafil plus tamsulosin.Meanwhile,the difference in SET was only significant between tadalafil plus tamsulosin versus tamsulosin.It appears that tadalafil and silodosin have similar efficacy in SET and SER.All medical expulsive therapies had comparable safety.展开更多
Dear Editor,We present the reported case of repetitive bilateral suprachoroidal expulsive hemorrhage(SEH)after anti-glaucoma surgeries.SEH is a rare but potentially devastating complication of intraocular surgery.Long...Dear Editor,We present the reported case of repetitive bilateral suprachoroidal expulsive hemorrhage(SEH)after anti-glaucoma surgeries.SEH is a rare but potentially devastating complication of intraocular surgery.Long-term ocular hypertension,high myopia,older age,arterial sclerosis,and aphakia have been reported as preoperative risk factors for developing SEH^([1]).The prognosis for the visual acuity is poor without proper management.A suggested time for surgical drainage is said to be 10-14d when the hemorrhagic clot begins to liquefy^([2]).展开更多
Twelve representative crude oil samples recovered from six oil fields in the Albertine Graben, Uganda were chosen for this study. The study aimed to understand the genetic relationships between the oils, the inferred ...Twelve representative crude oil samples recovered from six oil fields in the Albertine Graben, Uganda were chosen for this study. The study aimed to understand the genetic relationships between the oils, the inferred depositional environment of the source rocks, maturity of the crude oils, and to gain some insight on the expulsion of the oils from source rocks. The work involved geochemical bulk analysis （asphaltene and liquid chromatographic separations）, GC-FID （gas chromatography with a flame ionization detector）, and GC-MS （gas chromatography-mass spectrometry） of saturate and aromatic fractions. Bulk analysis shows that the oils are dominated by saturate hydrocarbon fractions （48.7%-62.0%） and are highly waxy （35-56.2 wt%） with low sulfur content （〈 0.1 wt%）. The high saturate hydrocarbon and high wax contents are probably due to organic matter input from land plants and/or long-chain alkanes from fresh water algae in lacustrine systems. The low sulfur contents alongside the high wax abundances are consistent with elastic-dominated source rock facies deposited in a non-stratified lacustrine environment. Data from GC-FID and GC-MS analyses such as n-alkane distributions, pristane/phytane ratios, biomarker terpane and sterane, dibenzothiophene and phenanthrene parameters show that the oils belong to a single family and were derived from a elastic predominantly algal source rock deposited under suboxic conditions in a non-stratified freshwater to brackish water lacustrine environment. The data further show that the oils have a very narrow range of maturities and are generated in the peak oil window. The observed narrow range of maturities and inferred lacustrine depositional setting for the source rocks suggest that the kerogen responsible for the generation of the oils is likely to be predominantly type-1 known to display narrow activation energies. This in turn implies that the expulsion of the oil from the source rock occurred as a quick single event hence, the filling of reservoirs in the Albertine Graben probably did not involve late stage expulsion and multiple charges of oil.展开更多
文摘The fracturing of the pressure compartments in sedimentary basins may not be caused completely by natural hydraulic fracturing. On the bases of fracture mechanics and numerical simulation, we consider that there are two mechanisms concerning the fracturing of pressure compartments, which are as follows: (1) natural hydraulic fracturing of the sediments within pressure compartments, and (2) tensile fracturing due to tangential traction. When the fracture, formed in the sediments within pressure compartments due to hydraulic fracturing, arrives at the base of the seal, the intensely tangential tensile stresses are created and lead to the fracturing of the seal. After the seal fractured, the fluid escaped from the pressure compartments. In a shallow pressure compartment, the duration of fracture opening and fluid expulsion is about 10-20 years in a cycle.
文摘Objective:Medical expulsive therapy(MET)is a suitable option for facilitating stone expulsion in patients with distal ureteral stones.This meta-analysis was conducted to compare efficacy and safety of monotherapy and combination therapy with tamsulosin,silodosin,and tadalafil on stone expulsion rate(SER)and stone expulsion time(SET),as well as their comparative safety,numbers of colic pain episodes,and need for analgesics.Methods:Randomized controlled trials were retrieved by searching PubMed,Scopus,and Web of Science up to November 27,2023.Hand-searching was also conducted in Google Scholar to find additional records.Papers in English that compared the safety and efficacy of at least two of the above agents in adults with distal ureteral stones≤10 mm were included.Results:In total,27 studies were identified(six studies through database searches and 21 through checking reference lists and hand-searching in Google Scholar).More than half of them(n=15,56%)were conducted in India.The SER significantly improved with silodosin compared with tamsulosin(odds ratio[OR]2.24,p<0.001),whereas the difference in SET was non-significant.Tadalafil achieved a significantly higher SER compared with tamsulosin(OR 1.42,p=0.042)without any difference in SET.Subgroup analysis of 5-and 10-mg doses of tadalafil showed no significant difference in SER or SET.We found no significant difference in need for analgesics(mean difference(MD−53.73,p=0.2)or the mean number of colic episodes(MD−0.42,p=0.060)between tadalafil and tamsulosin.SER or SET was not significantly different between silodosin and tadalafil.Tadalafil plus tamsulosin led to a significantly higher SER(OR 1.87,p<0.001)and SET(MD−2.99,p=0.002)compared with tamsulosin,without any significant difference in adverse effects.Conclusion:Compared with tamsulosin,SER significantly improved with silodosin,tadalafil,and the combination of tadalafil plus tamsulosin.Meanwhile,the difference in SET was only significant between tadalafil plus tamsulosin versus tamsulosin.It appears that tadalafil and silodosin have similar efficacy in SET and SER.All medical expulsive therapies had comparable safety.
基金Supported by National Natural Science Foundation of China(No.82171087No.82201228)+1 种基金Natural Science Foundation of Hunan Province(No.2024JJ6570)the Scientific Research Launch Project for new employees of the Second Xiangya Hospital of Central South University.
文摘Dear Editor,We present the reported case of repetitive bilateral suprachoroidal expulsive hemorrhage(SEH)after anti-glaucoma surgeries.SEH is a rare but potentially devastating complication of intraocular surgery.Long-term ocular hypertension,high myopia,older age,arterial sclerosis,and aphakia have been reported as preoperative risk factors for developing SEH^([1]).The prognosis for the visual acuity is poor without proper management.A suggested time for surgical drainage is said to be 10-14d when the hemorrhagic clot begins to liquefy^([2]).
文摘Twelve representative crude oil samples recovered from six oil fields in the Albertine Graben, Uganda were chosen for this study. The study aimed to understand the genetic relationships between the oils, the inferred depositional environment of the source rocks, maturity of the crude oils, and to gain some insight on the expulsion of the oils from source rocks. The work involved geochemical bulk analysis （asphaltene and liquid chromatographic separations）, GC-FID （gas chromatography with a flame ionization detector）, and GC-MS （gas chromatography-mass spectrometry） of saturate and aromatic fractions. Bulk analysis shows that the oils are dominated by saturate hydrocarbon fractions （48.7%-62.0%） and are highly waxy （35-56.2 wt%） with low sulfur content （〈 0.1 wt%）. The high saturate hydrocarbon and high wax contents are probably due to organic matter input from land plants and/or long-chain alkanes from fresh water algae in lacustrine systems. The low sulfur contents alongside the high wax abundances are consistent with elastic-dominated source rock facies deposited in a non-stratified lacustrine environment. Data from GC-FID and GC-MS analyses such as n-alkane distributions, pristane/phytane ratios, biomarker terpane and sterane, dibenzothiophene and phenanthrene parameters show that the oils belong to a single family and were derived from a elastic predominantly algal source rock deposited under suboxic conditions in a non-stratified freshwater to brackish water lacustrine environment. The data further show that the oils have a very narrow range of maturities and are generated in the peak oil window. The observed narrow range of maturities and inferred lacustrine depositional setting for the source rocks suggest that the kerogen responsible for the generation of the oils is likely to be predominantly type-1 known to display narrow activation energies. This in turn implies that the expulsion of the oil from the source rock occurred as a quick single event hence, the filling of reservoirs in the Albertine Graben probably did not involve late stage expulsion and multiple charges of oil.
