Direct Injection Research Articles

Acceleration of Modeling Capability for GDI Spray by Machine-Learning Algorithms

Cold start causes a high amount of unburned hydrocarbon and particulate matter emissions in gasoline direct injection (GDI) engines. Therefore, it is necessary to understand the dynamics of spray during a cold start and develop a predictive model to form a better air-fuel mixture in the combustion chamber. In this study, an Artificial Neural Network (ANN) was designed to predict quantitative 3D liquid volume fraction, liquid penetration, and liquid width under different operating conditions. The model was trained with data derived from high-speed and Schlieren imaging experiments with a gasoline surrogate fuel, conducted in a constant volume spray vessel. A coolant circulator was used to simulate the low-temperature conditions (−7 °C) typical of cold starts. The results showed good agreement between machine learning predictions and experimental data, with an overall accuracy R2 of 0.99 for predicting liquid penetration and liquid width. In addition, the developed ANN model was able to predict detailed dynamics of spray plumes. This confirms the robustness of the ANN in predicting spray characteristics and offers a promising tool to enhance GDI engine technologies.

Impact of nano cerium oxide addition with pyrolysis waste plastic oil on combustion, performance and emission characteristics of CRDI diesel engine

Abstract This investigation examined the effect of incorporating cerium oxide (CeO2) nanoparticle into diesel and waste plastic oil (WPO) blends on the combustion, performance and emission characteristics of the diesel engine. The WPO was extracted from low density polyethylene using plastic pyrolysis. The blending of diesel and WPO with combination of D70:WPO30 and D50:WPO50 was prepared to evaluate the engine operation. Additionally, the spherical sized CeO2 with 50 mg/L and 100 mg/L was added with this blend. The various blends named as Diesel, D-WPO30, D-WPO30+Ce50, D-WPO30+Ce100, D-WPO50, D-WPO50+Ce50 and D-WPO50+Ce100 were used in this investigation to operate the engine under various load conditions. The experiment was performed using water cooled common rail direct injection (CRDI) diesel engine with prepared D-WPO blend. Different characteristics such as In-cylinder pressure (CP), heat release rate (HRR), ignition delay time (IDT), brake thermal efficiency (BTE), brake specific fuel consumption (BSFC) and exhaust gas temperature (EGT), carbon monoxide (CO), hydrocarbon (HC), nitrogen oxide (NOx) and smoke opacity emission are studied with respect to the effect of different blends and applied load used. It was observed that increasing of CeO2 nanoparticles in blend improved the overall performance and emission of the engine. Form the results, D-WPO30+Ce100 blend showed enhanced brake thermal efficiency (BTE), brake specific fuel consumption (BSFC) and exhaust has temperature (EGT) are 28.2%, 3% and 465oC respectively. Similarly, reduced emission of CO, NOx, HC and smoke opacity was observed in the CeO2 added blends particularly at 100 mg/L. It was concluded that among all blends prepared, the D70:WPO30 with 100 mg/L of CeO2 showed improved combustion, performance and emission characteristics in proposed diesel engine.

Abstract 4138380: Cardiac protection of hiPSC-CMs loaded chitosan cardiac patch in myocardial infarcted swine

Background: The low grafting rate of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) following direct injection into the myocardium limits the efficacy of cardiac repair after myocardial infarction (MI). Chitosan-based scaffolds have emerged as functional biomaterials for designing delivery systems in cardiac therapies. This study aimed to enhance the potency of cardiac repair using a hiPSC-CMs loaded chitosan cardiac muscle patch (hCCMP). Methods: The patches were fabricated using chitosan. Characterization of the chitosan patches involved assessing their swelling rate and porosity. The biocompatibility of the hCCMP was analyzed through scanning electron microscopy (SEM) and the CCK8 assay. 16 Yorkshire swine (15-20 kg, 45-50 days of age) were randomly divided into 4 groups (n=4 per group): Sham, MI without further intervention, MI with an empty patch (without hiPSC-CMs), and MI with hCCMP implantation. One and four weeks post-MI, heart function, Infarction size, myocardial perfusion and metabolism were evaluated via cardiac PET-MRI. Engraftment was assessed through human cardiac troponin T staining. Histological analysis including left ventricular anterior wall thickness, cardiac remodeling, angiogenesis, arterialization, and apoptosis in the infarct border area were analyzed using immunofluorescence. Results: SEM showed that the chitosan patch had regular pore size and good 3D structure; porosity was about (96.7±0.37)%. On day3, the patch swelling rate was about (715±64.55)%. SEM, CCK8 assay showed a normal cells growth in the chitosan patch. The hiPSC-CMs grafted well with chitosan patch delivery systems and was associated with significantly improvement in LV function, infarction size, angiogenesis and cardiomyocyte apoptosis in pigs 4 weeks after MI. Conclusions: The 3D chitosan cardiac patch with hiPSC-CMs loaded can enhance the potency of cardiac repair in pigs after MI and present a novel and promising therapic strategy.

Transrectal ultrasound-guided intraprostatic injection therapy for treatment of chronic prostatitis in a Ugandan population

Abstract Background Globally, the clinical understanding of prostatitis has been obscured mainly due non-specificity of clinical features, no uniform diagnostic criteria and its protracted treatment course. Conventional treatment of chronic prostatitis by oral or parenteral routes of drug administration remains a challenge basically because of the poor ability of drugs to penetrate prostate epithelium; the alternative of direct prostate injection has not been thoroughly studied in an African population. The aim of this retrospective study was to determine the effect of transrectal ultrasound (TRUS)-guided intraprostatic injection of a cocktail of antibiotics, antifungal and long-acting steroids on alleviating symptoms attributed to chronic prostatitis in Ugandan patients. Methods We conducted a retrospective review of records among patients who were referred with symptoms attributed to chronic prostatitis at the Radiology Department of Ernest Cook Ultrasound Research and Education Institute (ECUREI). Patients were treated using TRUS-guided intraprostatic injection of a cocktail of antibiotics, antifungal agents and long-acting steroids. Results At baseline, we found that out of the 131 patients, 90 had pain or burning during urination in the last week to seeking care and 89 had symptoms, which had kept them away from doing the kinds of things they would usually do. Additionally, 85 of the total number of patients felt terrible about their symptoms. Post intervention, after 1 year following completion of intraprostatic injection therapy (IPIT), we found that most patients had mild residual symptoms which were largely; mild pain and burning at urination. None of the patients had symptoms, which kept them away from doing the kind of things they would usually do. Furthermore, 62 patients felt delighted about their quality of life, whereas prior to treatment, none was delighted. Eighty-five patients had felt terrible about their quality of life prior to the IPIT, but post therapy, no patient felt terrible. Conclusion Transrectal ultrasound-guided intraprostatic injection therapy of a drug cocktail composed of antibiotics, antifungal agents, long-acting steroids and lidocaine for treatment of patients presenting with symptoms attributed to chronic prostatitis and refractory to conventional oral therapy has shown a good response in this study.

Botulinum toxin type A treatment for a parotid gland injury in two adult horses

SummaryThe most common disorder affecting the salivary glands in horses is trauma to the parotid gland or duct. Several management techniques have been described, each with their own set of complications. The objective of this case report was to describe the direct injection of botulinum toxin type A into the parotid gland and its outcome in two clinical cases involving damage to either the parotid salivary gland or its duct. Both cases involved iatrogenic damage to either the parotid salivary gland or its duct. Treatment for both cases involved the injection of 200 units of botulinum toxin type A into the parotid gland in order to reduce salivary production and to prevent the potential development of a chronic fistula. Follow‐up assessment after the treatment was conducted via telephone consultation and photographs from the owners. In both clinical cases, a marked reduction in saliva production from the parotid gland was noted within 2 days after toxin injection and the wounds healed without complication. In the first case, the treatment was repeated after 3 weeks. No short‐ or long‐term side effects after injection were reported by the owners. Limitations were the small number of cases and the lack of literature regarding the dose and treatment regime for botulinum toxin type A in horses. It was concluded that the administration of botulinum toxin type A appears to be a safe and effective therapeutic alternative or complementary procedure for the treatment and prevention of parotid gland or duct fistulas in horses.

Direct aqueous injection LC−ESI-MS/MS analysis for the determination of 23 EU watch list substances in whole water samples

The Watch List (WL) monitoring program in the European Union (EU) aims to identify and prioritize emerging pollutants in the aquatic environment that may pose risks to human health and the environment. Thus, reliable methods are needed to determine these substances. This study presents the development of a simple, fast, and green method for analysing 23 WL substances (4 antibiotics, 9 azole compounds, 6 other pesticides, and 4 sunscreens), covering a range of medium to very low polarity (log Kow 2.2–6.9), in whole environmental water samples using direct aqueous injection (DAI) in combination with liquid chromatography–electrospray ionization tandem mass spectrometry (LC–ESI-MS/MS). To process the samples, 0.5 mL of acetonitrile is added to 1 mL of raw water, followed by brief shaking. The mixture is then centrifuged to remove sedimented suspended solids before being injected into the LC instrument. A rigorous analytical greenness metric for sample preparation (AGREEprep) assigned this procedure a green score of 0.61. The method showed satisfactory performance characteristics for all analytes under investigation, including limits of quantification meeting the WL requirements, recoveries in the range of 79–120%, and intra-day precision with relative standard deviations in the range of 1.9–20%. The method is suitable for screening and monitoring purposes, as confirmed by the analysis of real samples.

Analysis of volatile compounds in Xiangjiao baijiu from different storage containers and years based on HS-GC-IMS and DI-GC–MS

The volatile compounds in 16 different storage containers and years of Xiangjiao Baijiu (XJBJ) were compared and analyzed via direct injection (DI) combined with gas chromatography–mass spectrometry (GC–MS) and headspace extraction (HS) coupled with gas chromatography-ion mobility spectrometry (HS-GC-IMS) for the first time. Through HS-GC-IMS analysis, it was found that the succession rules of 14 compounds such as furfural during aging process. A total of 60 compounds were identified using DI-GC–MS. Twenty-five of these compounds were further quantified, and 18 compounds had odor activity values (OAVs) > 1, which were important contributor to aroma of XJBJ. Among them, those with OAVs >1000 included ethyl hexanoate, ethyl octanoate, ethyl butanoate, and ethyl pentanoate. Combining the results of quantitative, OAVs and partial least squares-discriminant analysis (PLS-DA) revealed that 10 compounds such as ethyl octanoate were the important compounds that lead to the differences between different storage types of XJBJ.

Microscopic and macroscopic analysis of the flashing and non-flashing ethanol blended fuel for the direct injection sprays

Microscopic and macroscopic analysis of the flashing and non-flashing ethanol blended fuel for the direct injection sprays

CFD unified approach under Eulerian-Lagrangian framework for methanol and gasoline direct injection sprays in evaporative and flash boiling conditions

Innovative synthetic fuels for advanced propulsion systems, such as methanol and ammonia, and synthetic blended fuels (E00, E10, and E30), known for their high volatility, are often injected directly into combustion chambers. It follows that Eulerian-Lagrangian spray models need to accurately capture the spray collapse as a consequence of flash boiling onset and be capable of proficiently handling the preferential evaporation of multi-component fuels in evaporative scenarios.So, we performed the assessment of an Eulerian-Lagrangian CFD code for simulating methanol and E00 gasoline blend sprays in both early and late injection conditions involving flash boiling conditions and preferential evaporation. The adoption of an effervescent breakup model and of a non-equilibrium phase transition model for the discrete phase allows the adoption of a setup that is almost completely free from specific constant tuning, especially for what concerns the breakup model. We validated the simulations using experimental PLV maps of methanol and E00 sprays issued from the ECN Spray M injector. The results highlight a significantly different morphology of the methanol spray compared to the E00 one under late injection conditions. Under stratified combustion, low-volatile fuels are likely to be ignited first, and the flame propagates toward the high-volatile fuels. The spray collapse was also correctly reproduced, inducing the presence of a low-pressure zone and modifying the spray morphology.

Future Technological Directions for Hydrogen Internal Combustion Engines in Transport Applications

The paper discusses some of the requirements, drivers, and resulting technological paths for manufacturers to develop hydrogen combustion engines for use in two types of market application – on-road heavy- and light-duty. One of the main requirements is legislative certainty, and this has now been afforded – at least in the major market of Europe – by the European Union's recent adoption into law of tailpipe emissions limits specifically designed to encourage the uptake of hydrogen engines in heavy-duty vehicles, giving manufacturers the confidence they need to invest in productionized solutions to offer to customers.It then discusses combustion systems and boosting systems for the two market types, emphasizing that heavy-duty vehicles need best efficiency throughout their operating map while light-duty ones, since they are rarely operated at full load, will mainly primarily need efficiency in the part-load region. This difference will likely cause a divergence in solutions, with heavy-duty engines running very lean everywhere and light-duty ones likely operating at the stoichiometric air-fuel ratio, at least for most of the map. The impacts of the strategies on engine systems and vehicle integration are discussed.It is postulated that due to reasons of preignition avoidance and efficiency hydrogen engines will rapidly adopt direct injection and that the long-term heavy-duty types will migrate towards the typical current spark-ignition-type cylinder head architecture where tumble, rather than swirl, will ultimately be needed for air motion in the cylinder for these reasons. They may also adopt active pre-chamber technology to ignite extremely lean mixtures for maximum efficiency and minimum emissions of oxides of nitrogen.It is suggested that light-duty engines will evolve less from their current gasoline architectural norm since they already contain all of the necessary fundamentals for hydrogen combustion. However, since part-load efficiency will be important, some new strategies may become desirable. Developing dual-fuel light-duty engines could accelerate their uptake as the heavy-duty market simultaneously accelerates the creation of the fuel supply infrastructure.The likely technological evolution suggests that variable valve trains, and specifically cam profile switching technology, would be extremely useful for all types of hydrogen engine, especially since they are readily available in different gasoline engines now. New operating strategies afforded by variable valve trains would benefit both heavy- and light-duty engines, and these strategies will become more sophisticated. There will therefore likely be a convergence of technologies for the two markets, albeit with some key differences maintained due to their vehicle applications and their differing operation in the field.

A matrix-centered view of mass spectrometry platform innovation for volatilome research.

Volatile organic compounds (VOCs) are carbon-containing molecules with high vapor pressure and low water solubility that are released from biotic and abiotic matrices. Because they are in the gaseous phase, these compounds tend to remain undetected when using conventional metabolomic profiling methods. Despite this omission, efforts to profile VOCs can provide useful information related to metabolic status and identify potential signaling pathways or toxicological impacts in natural or engineered environments. Over the past several decades mass spectrometry (MS) platform innovation has instigated new opportunities for VOC detection from previously intractable matrices. In parallel, volatilome research linking VOC profiles to other forms of multi-omic information (DNA, RNA, protein, and other metabolites) has gained prominence in resolving genotype/phenotype relationships at different levels of biological organization. This review explores both on-line and off-line methods used in VOC profiling with MS from different matrices. On-line methods involve direct sample injection into the MS platform without any prior compound separation, while off-line methods involve chromatographic separation prior to sample injection and analyte detection. Attention is given to the technical evolution of platforms needed for increasingly resolved VOC profiles, tracing technical progress over time with particular emphasis on emerging microbiome and diagnostic applications.

Online LC-Orbitrap MS method for the rapid molecular characterization of dissolved organic matter.

High-resolution mass spectrometry (HRMS) combined with electrospray ionization (ESI) has been the most useful technique for molecular characterization of dissolved organic matter (DOM) derived from diverse sources. However, the comprehensive detection of DOM composition was hindered by ionization suppression observed in ESI sources. HRMS coupled with liquid chromatography (LC) is a potential tool for comprehensive molecular characterization of DOM. The Suwannee River fulvic acids (SRFAs) and two DOM samples from seawater and refinery wastewater extracted by solid phase extraction (SPE) were analyzed by LC-Orbitrap MS coupled with ESI. The mobile phases, solvent composition, and gradient in the LC-Orbitrap MS analysis were optimized. The number of detected molecular formulae of SRFAs by online LC-Orbitrap MS was significantly increased by approximately 40% compared to direct injection. These additional detected compounds are mainly protein and lignin-like compounds, with a low O/C ratio and high H/C ratio. For the SRFAs, the relative standard deviations (%) of reproducibility are 5.51, 2.33, 7.97, and 1.80 for average O/C, H/C, double bond equivalent, and modified aromaticity index, respectively. This study proposed a simple and rapid method based on LC-Orbitrap MS for an in-depth analysis of the molecular composition of DOM, achieving a remarkable analysis time of only 5 min per sample. The rapid method provides a dependable and efficient approach for the molecular characterization of DOM, thereby advancing our comprehension and investigation of DOM across diverse ecosystems.

Experimental study of vegetable oil droplets vaporization under low temperature conditions such as those found in diesel engine cold parts

This paper presents an analysis of three vegetable oil droplets vaporization process in the range temperature from 473 to 723 K corresponding to low temperature conditions found in diesel engine cold parts. This process is analyzed for a droplet evaporating in a hot environment at atmospheric pressure using the fiber-suspended droplet technique well used in the literature, and analyzing the droplet normalized square diameter and temperature evolution surrounding the droplet when vaporizing. The main difference between those already studied in literature is the range temperature which varies between 473 and 723 K in which vegetable oils vaporizing problems leading to deposits formation in the cold regions of diesel engines especially in direct injection. This presents a scientific challenge for resolving deposit formation. The findings reveal that vegetable oil droplets experience expansion and heating for temperatures below 623 K: no other changes are observed. Between temperatures of 623 and 683 K, an increase in temperature, expansion, and an inconsistent vaporization is observed. This is followed by a phase of low and constant vaporization. From 683 K, vegetable oils experience an initial stage of heating and expansion, which is accompanied by a phenomenon of puffing and bursting. Finally, in the last phase, residue formation occurs. Puffing and bursting phenomena manifest once the temperature reaches 683 K, indicating the emergence of substantial quantities of light compounds including carboxylic acids, aromatics, acrolein, ketene, and fatty acids. These compounds are formed through the thermal degradation and polymerization of vegetable oils. This process causes deposits to form in the colder areas of diesel engines.

Performance assessment of direct injection stoichiometric and lean burn compressed natural gas engine over port fuel gasoline and compressed natural gas engine

ABSTRACT A direct injection (DI) CNG engine was developed and evaluated under stoichiometric and lean burn conditions, emphasising high compression ratios (CRs). A comparative analysis of PFI gasoline and PFI CNG engines was conducted to provide comprehensive insights. Results showed that the DI CNG engine exhibited a shorter combustion duration, indicating higher combustion speed, and enhanced combustion stability, particularly at low load and speed conditions, with a reduced coefficient of variation of indicated mean effective pressure (COVIMEP) below 1%. The DI CNG engine demonstrated a relative increase in net indicated thermal efficiency by 4–5% compared to the PFI CNG engine. Furthermore, CNG engines operating at a high compression ratio of 16 could run at high loads without encountering knocking issues. Lean burn operation, combined with high compression ratios, improved thermal efficiency while minimising emissions; however, challenges such as combustion instability and increased emissions under lean burn conditions were observed.

Possibility of identifying 1H-indolylaminium trifluoroacetates with antimicrobial activity by mass spectrometry

The present study proposes a convenient approach to identify a series of novel substituted 1H-indol-5-,6-ylaminium trifluoroacetates with antimicrobial activity based on mass spectral data obtained using direct injection into an ion source at an elevated temperature when the salts decompose with the release of counterions: acids and organic bases – substituted 1H-indolylamines. By the presence of ions with m/z 69, 45, 28, 17 in the spectra, it is judged that the salts are formed by trifluoroacetic acid. Using the available literature data on the mass spectrometry of substituted indoles, aromatic amines, and carboxylic acids, substantiated schemes for the decomposition of molecular ions of organic bases, 1H-indolylamines, are compiled and discussed, in which the mechanism of formation and the structure of fragment ions arising under electron ionization conditions are given. The revealed general, as well as individual for individual representatives with a certain character and place of substitution in the indole bicycle, patterns of behavior of 1H-indolylamine radical ions under conditions of high-temperature mass spectral imaging make it possible to judge their structure and, in general, the structure of 1H-indolylamine trifluoroacetates. The approach used in this work can also be used to prove compounds of a similar group based on the analysis of their mass spectra.

STUDYING THE EFFECT OF MAGNETIC FLUX ON DIESEL FUEL LINE ON SOME PERFORMANCE AND EMISSION OF DIESEL ENGINE

This study aimed to investigation was carried out to evaluate the performance and product emission of four cylinder 4- stroke water cooled direct injection (DI) diesel engine fueled by permanent magnet exposed diesel fuel compared with diesel fuel (DF). Three levels of magnet field intensity were used including Diesel fuel exposer to 3000 Gauss (DG3), Diesel fuel exposer to 5000 Gauss (DG5) and Diesel fuel exposer to 9000 Gauss (DG9) fuel respectively. Permanent magnetic device was employed and installed on fuel line before interring high pressure fuel injection pump . The engine run at constant speed 1500rpm(revolution per minute) and loaded by two levels 4.5 kW and 9 kW represented as L1and L2 respectively. Results obtained showed that fuel DG5 registered an increased in thermal efficiency(TE) about 20.09% at load L1 compared with DF. Maximum reduction in brake specific fuel consumption (bsfc) about 12.12%, when using DG5 fuel at load 1 compared to DF fuel. All exhaust emission Unburned Hydrocarbon (UHC), Carbon Monoxide (CO), Carbon Dioxide (CO2),Particular Maters (PM), and Nitrogen Oxides (NOx) are decreased when diesel fuel treated with different magnetic intensities 3000,5000 and 9000 Gauss. Compared with conventional diesel fuel. Maximum reduction in PM,HC,NOx,CO2,and CO about 16.56-27.08%, 3.89–64.26%, 4.79–7.91%, 4.05-5.71and 11.46-53.48% respectively. CO2 emission was increased by 1.65-4.28 at DG5 with L1 and L2 respectively due to the operating conditions.

USP13 Overexpression in BMSCs Enhances Anti-Apoptotic Ability and Guards Against Methylprednisolone-Induced Osteonecrosis in Rats.

Methylprednisolone (MPS) use is linked to increased cases of osteonecrosis of the femoral head (ONFH). Bone marrow mesenchymal stem cells (BMSCs) have shown potential for treating MPS-induced ONFH, but their effectiveness is limited by high apoptosis rates post-transplantation. We developed a pre-treatment strategy for BMSCs to improve their viability. In a rat model of MPS-induced ONFH, we evaluated the effects of USP13 overexpression in BMSCs through micro-CT, HE staining, and TUNEL staining. USP13-overexpressing BMSCs significantly reduced ONFH severity compared to plain BMSCs and direct lentivirus injection. USP13 also protected BMSCs from MPS-induced apoptosis by modulating PTEN and reducing AKT phosphorylation. This led to decreased expression of apoptotic genes and proteins in USP13-overexpressing BMSCs. Our findings highlight USP13 as a promising target for enhancing BMSC survival and efficacy in treating MPS-induced ONFH.

Influence of steam induction on the performance and hydrogen knock limit of a hydrogen-gasoline spark ignition engine

This study examines the effect of steam induction on the performance and hydrogen knock limit of a hydrogen-gasoline dual-fuel Spark Ignition (SI) engine. The experimental setup includes gasoline direct injection, along with steam and hydrogen port induction. Steam-to-fuel ratios of 7.5 %, 15 %, and 22.5 % were used, and hydrogen was introduced in step sizes of 2 LPM until knock onset. The extension of the hydrogen knock limit was achieved through steam induction and retarding spark timing. Under the default configuration, the maximum achievable hydrogen flow rate was 8 LPM, which increased to 20 LPM with retarded spark timing and 22.5 % steam proportion. Steam induction initially increased and then decreased brake thermal efficiency, brake mean effective pressure, in-cylinder pressure, and heat release rate. In contrast, advancing spark timing and hydrogen enrichment consistently improved performance and combustion characteristics. Cyclic variation showed a decreasing trend with the introduction of steam and hydrogen. Unlike hydrogen enrichment, steam addition reduced CO and NOX emissions.

Intravenous injection versus transhepatic intracholecystic injection of indocyanine green (ICG) to outline biliary tree during laparoscopic cholecystectomy

BackgroundTo potentially lessen injuries and associated complications, fluorescence cholangiography has been suggested as a technique for enhancing the visualization and identification of extrahepatic biliary anatomy. The most popular way to administer indocyanine green (ICG) is intravenously, as there is currently little data on ICG injections directly into the gallbladder. In order to visualize extrahepatic biliary anatomy during laparoscopic cholecystectomy (LC), we compared the two different ICG administration techniques. We also examined variations in visualization time, as well as the effectiveness, benefits, and drawbacks of each modality.MethodsIn this prospective randomized clinical study, 60 consecutive adult patients with chronic and acute gallbladder disease were included. Our study conducted from 2022 to 2024 in Surgical Department of Theodor Bilharz Research Institute. Thirty patients underwent LC with intravenous ICG administration (IV-ICG), thirty patients received a direct injection of gallbladder through transhepatic ICG (IC-ICG) and Preoperative, intraoperative, and postoperative patient data were examined.ResultsIn terms of their perioperative and demographic features, the groups were similar. Without a statistically significant difference, the IV-ICG group’s total operating time was less than that of the IC-ICG group (p 0.140). Compared to the transhepatic IC-ICG method, IV-ICG was more accurate in identifying the duodenum and the common hepatic duct (p = 0.029 and p = 0.016, respectively). In the transhepatic IC-ICG and IV-ICG groups, the cystic duct could be identified prior to dissection in 66.6% and 73.3% of cases, respectively, and this increased to 86.6% and 93.3% following dissection. In the transhepatic IC-ICG group, the common bile duct was visible in 93.3% of cases; in the IV-ICG group, it was visible in 90% of cases. Two cases in the IC-ICG group and every case following IV-ICG administration had liver fluorescence (6.6% versus 100%; p < 0.001).ConclusionThe current study shows that for both administration methods, ICG-fluorescence cholangiography can be useful in identifying the extrahepatic biliary anatomy during Calot’s triangle dissection. By avoiding hepatic fluorescence, the transhepatic IC-ICG route can increase the bile duct-to-liver contrast with less expense and no risk of hypersensitivity reactions than the intravenous ICG injection method. We recommend to use both techniques in case of acute cholecystitis with cystic duct obstruction. In cases of liver cirrhosis, we recommend transhepatic IC-ICG as IV-ICG is limited.

Origin of the Oligocene–Miocene Sailipu ultrapotassic volcanic rocks in southern Tibet: Melting of Asian mantle pyroxenites triggered by eastward tearing of the subducting Indian continental slab

Widely distributed Oligocene−Miocene ultrapotassic volcanic rocks in the Lhasa terrane of southern Tibet have been associated with the melting of the lithospheric mantle, plateau uplift, and porphyry Cu-Au mineralization. This study presents the mineral chemistry of olivine and clinopyroxene phenocrysts, whole-rock major and trace element data, and zircon U-Pb geochronological and Hf isotopic data for the Sailipu primitive ultrapotassic volcanic rocks. The Sailipu volcanic rocks exhibit high MgO (5.6−11.4 wt%), Cr (386−981 ppm), Co (22−43 ppm), and Ni (95−423 ppm) concentrations and have highly fractionated rare earth elements [REEs; (La/Yb)N = 23−73] and high-Fo (89.1−90.8) olivine phenocrysts containing elevated NiO (up to 0.59 wt%), which suggests a pyroxenitic mantle source that partially melted in the garnet stability field. Their high K2O contents (4.8−8.0 wt%) and global subduction sediment-like trace element patterns suggest that the metasomatic agents, which reacted with mantle peridotites to form phlogopite-bearing pyroxenites, were dominantly derived from the melting of subducted continental sediments. Their high whole-rock Ba/La and Th/Nd ratios are consistent with this hypothesis. The Sailipu ultrapotassic volcanic rocks also exhibit low initial 176Hf/177Hf ratios that resemble those of Himalayan leucogranites, and high Ca contents in olivine phenocrysts, which is consistent with contributions from the subducted carbonate-rich sedimentary strata on top of the thinned Greater Indian continental crust. The zircon U-Pb chronological data yielded concordant ages of 24.33 ± 0.19 Ma, 21.20 ± 0.62 Ma, and 17.05 ± 0.31 Ma for different exposures of the Sailipu volcanic rocks, which establishes a maximum age of ca. 24 Ma for these rocks. The northwest−southeast spatial distribution and the southeastward decrease in age (80°E−90°E) suggest west-to-east tearing of the thinned Greater Indian slab, which caused asthenospheric upwelling and melting of the Tibetan lithospheric mantle. Geothermometric calculations show relatively high primary magma temperatures (∼1250 °C) that are consistent with asthenospheric upwelling. We propose a mechanism that could genetically link the coeval Cu-Au ore-forming granitoids with the ultrapotassic magmatism of the Gangdese belt. The ultrapotassic rocks supply a large-volume of external magmatic volatiles, particularly H2O, which could trigger melting of the Tibetan lower crust and lead to the generation of the ore-forming granitoids and the establishment of oxidizing conditions for porphyry deposits. The oxygen fugacity (log ƒO2 values of ΔFMQ) of the primitive Sailipu ultrapotassic volcanic rocks (ΔFMQ = 0.48 ± 0.51 based on the Dol/melt V oxybarometer and ΔFMQ = 0.33 ± 1.19 according to the magmatic zircon U-Ce-Ti oxybarometer) is slightly lower than that of porphyry Cu-Au ore-forming granitoids in the eastern Gangdese (ΔFMQ = +0.8 to +2.9), which suggests that the direct injection of ultrapotassic melts into ore-forming granitoids played a limited role in changing oxygen fugacity, but more oxidized fluids/volatiles exsolved from these ultrapotassic melts may have facilitated the remelting of sulfide-bearing lower crust and/or directly scavenged sulfides from the mush-state reservoirs of the ore-forming granitoids in the middle−upper crust.