Rapid and Complete Digestion of Refractory Geological Samples Using Ultrafine Powder for Accurate Analyses of Trace Elements.

Complete sample digestion is a prerequisite for acquiring high-quality analytical results for geological samples. Closed-vessel acid digestion (bomb) has typically been used for the total digestion of refractory geological samples. However, the long digestion time (4-5 days) and insoluble fluoride complexes still pose challenges for digesting refractory geological samples using this approach. In this study, an efficient and simplified digestion technique combining ultrafine powders from planetary ball milling with bomb digestion was developed for trace element analysis of refractory geological samples: peridotite and granitoid. The method shows two significant improvements compared with previous approaches. (1) By performing dry planetary ultrafine milling, the initial 200 mesh peridotite (<74 µm) could be reduced to 800 mesh (<20 µm) in 6 min at a ball-to-powder mass ratio of approximately 15 using 3 mm tungsten carbide milling balls. (2) Complete peridotite and granitoid dissolution were achieved in approximately 2 h, 60 times faster than what is achievable using previous methods (2 h vs 120 h). Moreover, ultrafine powders effectively suppressed insoluble fluoride formation during bomb digestion. A suite of peridotite and granitoid reference materials were measured to evaluate the stability of this method. This efficient, simple, and reliable sample digestion method could benefit geological, food, environmental, and other fields requiring solid sample decomposition via wet acid, fusion, combustion, or dry ashing.

Establishment of Indirect Competitive Enzyme-linked Immunosorbent Assay (ic-ELISA) for Copper ion (Cu2+) in Raw Meat Products.

Adding an appropriate amount of copper to feed can promote the growth and development of livestock; however, a large amount of heavy metal copper can accumulate in livestock through the enrichment effect, which poses a serious threat to human health. Traditional Cu2+ detection relies heavily on complex and expensive instruments, such as inductively coupled plasma-optical emission spectrometry (ICP-OES) and inductively coupled plasma-mass spectrometry (ICP-MS); thus, convenient and simple rapid detection technologies are urgently needed. In this paper, synthesized copper antigens were used to immunize mice and highly specific anticopper monoclonal antibodies were obtained, which were verified to exhibit high affinity and specificity. Based on the above antibodies, an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) was established for the rapid detection of copper content in pork. The standard inhibition curve of the method was obtained by antigen-antibody working concentration screening, in which the half inhibitory concentration (IC50) was 11.888 ng/mL, the limit of detection (LOD) was 0.841 ng/mL and the correlation coefficient R2 of the curve was 0.998. In the additive recovery experiment, the recovery rate ranged from 90% to 110%, and the coefficient of variation (CV) was less than 10%, indicating that the method achieved high accuracy and precision. Finally, the results of ic-ELISA combined with Bland-Altman analysis showed a high correlation with ICP-MS, and the correlation coefficient (R2) reached 0.990 when the copper concentration was less than 200 ng/mL. Thus, the ic-ELISA method exhibits high reliability.

A deep learning-based semiautomated workflow for triaging follow-up MR scans in treated nasopharyngeal carcinoma.

It is imperative to optimally utilize virtues and obviate defects of fully automated analysis and expert knowledge in new paradigms of healthcare. We present a deep learning-based semiautomated workflow (RAINMAN) with 12,809 follow-up scans among 2,172 patients with treated nasopharyngeal carcinoma from three centers (ChiCTR.org.cn, Chi-CTR2200056595). A boost of diagnostic performance and reduced workload was observed in RAINMAN compared with the original manual interpretations (internal vs. external: sensitivity, 2.5% [p = 0.500] vs. 3.2% [p = 0.031]; specificity, 2.9% [p < 0.001] vs. 0.3% [p = 0.302]; workload reduction, 79.3% vs. 76.2%). The workflow also yielded a triaging performance of 83.6%, with increases of 1.5% in sensitivity (p = 1.000) and 0.6%-1.3% (all p < 0.05) in specificity compared to three radiologists in the reader study. The semiautomated workflow shows its unique superiority in reducing radiologist's workload by eliminating negative scans while retaining the diagnostic performance of radiologists.

Enantioselective effect of the chiral fungicide tebuconazole on the microbiota community and antibiotic resistance genes in the soil and earthworm gut.

Tebuconazole, consisting of two enantiomers, has a high detectable rate in the soil. The residue of tebuconazole in the soil may cause risk to microbiota community. Antibiotic resistance genes (ARGs) are considered as emerging environmental contaminants, and they can be transferred vertically and horizontally between microbiota community in the soil. Until now, the enantioselective effect of tebuconazole on the microbiota community and ARGs in the soil and earthworm gut has remained largely unknown. Tebuconazole enantiomers showed different bioconcentration behaviors in earthworms. The relative abundances of bacteria belonging to Actinobacteriota, Crenarchaeota and Chloroflexi in R-(-)-tebuconazole-treated soil were higher than those in S-(+)-tebuconazole-treated soil at same concentrations. In the earthworm gut, bacteria belonging to Proteobacteria and Bacteroidota exhibited different relative abundances between the S-(+)-tebuconazole and R-(-)-tebuconazole treatments. The numbers and abundances of ARGs in the soil treated with fungicides were higher than those in the control. In earthworm gut, the diversities of ARGs in all treatments were higher than that in the control, and the relative abundances of Aminoglycoside, Chloramphenicol, Multidrug resistance genes and mobile genetic elements (MGEs) in R-(-)-tebuconazole-treated earthworm gut were higher than those in S-(+)-tebuconazole-treated earthworm gut. Most of ARGs showed a significantly positive correlation with MGEs. Based on network analysis, many ARGs may be carried by bacteria belonging to Bacteroidota and Proteobacteria. These results provide valuable information for understanding the enantioselective effect of tebuconazole on the microbiota community and ARGs.

Genetic alterations in LEP and ADIPOQ genes and risk for breast cancer: a meta-analysis.

Introduction: Breast cancer has a strong genetic predisposition, and its genetic architecture is not fully understood thus far. In this study, we aimed to perform a meta-analysis to evaluate the association of genetic alterations in LEP and ADIPOQ genes, as well as their receptor-encoded genes with risk for breast cancer. Methods: Only published studies conducted in humans and written in English were identified by searching PubMed, SCOPUS, CINAHIL and Embase from their inception to October 2022. Eligibility assessment and data collection were completed independently by two researchers. Statistical analyses were done using the STATA software. Results: After literature search, 33 publications were eligible for inclusion. Overall, LEP gene rs7799039-G allele (odds ratio [OR]: 0.78, 95% confidence interval [CI]: 0.62 to 0.98) and ADIPOQ gene rs1501299-T allele (OR: 1.41, 95% CI: 1.06 to 1.88) were associated with the significant risk of breast cancer. In subgroup analyses, differences in menopausal status, obesity, race, study design, diagnosis of breast cancer, genotyping method and sample size might account for the divergent observations of individual studies. Circulating leptin levels were comparable across genotypes of LEP gene rs7799039, as well as that of LEPR gene rs1137101 (P>0.05). Begg's funnel plots seemed symmetrical, with the exception of LEPR gene rs1137100 and ADIPOQ gene rs1501299. Discussion: Taken together, we found, in this meta-analysis, that LEP gene rs7799039 and ADIPOQ gene rs1501299 were two promising candidate loci in predisposition to breast cancer risk.

High-precision zinc isotopic characterization of twenty soil reference materials from China determined by MC-ICP-MS.

Zinc isotopic ratios serve as powerful tools for tracing biochemical cycling of metals at Earth's surface, including the distribution, transportation, and enrichment of zinc (Zn) in soil. To conduct such studies and enable inter-laboratory comparisons, high-precision Zn isotopic measurements require the use of soil reference materials (RMs). However, there have been limited reports on the high-precision Zn isotope ratios of soil RMs thus far. In this study, we have developed a two-step Zn chemical separation protocol utilizing Bio-Rad AG MP-1M resin columns. This method has demonstrated excellent reproducibility for measuring the external δ66Zn values (relative to JMC-Lyon) of standard soil reference materials over an extended time period, with a better than 0.06‰ (2SD) precision. Remarkably, this study is the first to report the Zn isotopic compositions of 20 soil reference materials from various soil types in China. With the exception of one sample obtained from a mining area, the Zn isotopic compositions of all the analyzed soil reference materials exhibit remarkable similarity, with an average δ66Zn value of 0.31 ± 0.12‰, which aligns closely with the values observed in igneous rocks. The exceptional sample, with a higher δ66Zn value of 0.61 ± 0.02‰, indicates potential contamination during mining activities.

Low-cost and sensitive method for Pb isotope determination using a novel ß-Si3N4 emitter by thermal ionization mass spectrometry.

Thermal ionization mass spectrometry (TIMS) is the workhorse for lead isotopic ratio analysis due to its excellent precision. Silica gel as ionization activator on Re filament is proved to the best emitter that can provide excellent sensitivity even small Pb sample size. However, the price of Re filament is three times that of Ta filament that leads to high experimental cost for TIMS laboratory. Here, we first present a novel silicon nitride (ß-Si3N4) emitter on the Ta filament with good sensitivity for Pb isotopic ratio measurements. Hence, the cost of filament material is cut down ∼70%. The ß-Si3N4 emitter can yield stable and long-life Pb+ signal, about 2-3 V 208Pb and 0.65-0.90 V 208Pb for 20 ng and 5 ng NIST SRM981 sample size that is applicable to the most geological materials for bulk analysis. A suite of silicate reference materials were analyzed to verify the reliability and accuracy of our method. For 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb isotope ratios of geological samples, excellent internal precisions (2 SE) of ±0.005%-0.013% are achieved. Replicate digestions and analyses of the basalt standard BCR-2 and coal fly ash standard GBW08401 demonstrate that good external precision is obtainable that is 0.10-0.18% (n = 6, 2 SD) for 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb ratios.

Add-on individualizing prediction of nasopharyngeal carcinoma using deep-learning based on MRI: A multicentre, validation study.

In nasopharyngeal carcinoma, deep-learning extracted signatures on MR images might be correlated with survival. In this study, we sought to develop an individualizing model using deep-learning MRI signatures and clinical data to predict survival and to estimate the benefit of induction chemotherapy on survivals of patients with nasopharyngeal carcinoma. Two thousand ninety-seven patients from three independent hospitals were identified and randomly assigned. When the deep-learning signatures of the primary tumor and clinically involved gross cervical lymph nodes extracted from MR images were added to the clinical data and TNM staging for the progression-free survival prediction model, the combined model achieved better prediction performance. Its application is among patients deciding on treatment regimens. Under the same conditions, with the increasing MRI signatures, the survival benefits achieved by induction chemotherapy are increased. In nasopharyngeal carcinoma, these prediction models are the first to provide an individualized estimation of survivals and model the benefit of induction chemotherapy on survivals.

Artificial intelligence for assisting cancer diagnosis and treatment in the era of precision medicine.

Over the past decade, artificial intelligence (AI) has contributed substantially to the resolution of various medical problems, including cancer. Deep learning (DL), a subfield of AI, is characterized by its ability to perform automated feature extraction and has great power in the assimilation and evaluation of large amounts of complicated data. On the basis of a large quantity of medical data and novel computational technologies, AI, especially DL, has been applied in various aspects of oncology research and has the potential to enhance cancer diagnosis and treatment. These applications range from early cancer detection, diagnosis, classification and grading, molecular characterization of tumors, prediction of patient outcomes and treatment responses, personalized treatment, automatic radiotherapy workflows, novel anti-cancer drug discovery, and clinical trials. In this review, we introduced the general principle of AI, summarized major areas of its application for cancer diagnosis and treatment, and discussed its future directions and remaining challenges. As the adoption of AI in clinical use is increasing, we anticipate the arrival of AI-powered cancer care.

hnRNPA2B1 regulates the alternative splicing of BIRC5 to promote gastric cancer progression.

BACKGROUND: Systematic profiling studies have implicated regulators of pre-mRNA splicing as important disease determinants in gastric cancer (GC), but the underlying mechanisms have remained elusive. Here we focused on hnRNPA2B1 splicing factor-dependent mechanisms governing GC development. METHODS: The expression of hnRNPA2B1 was analyzed among the Cancer Genome Atlas (TCGA) datasets of GC and validated at mRNA level. The function of hnRNPA2B1 in GC cells was analyzed and its downstream gene was identified using RNA immunoprecipitation. Further, effect of hnRNPA2B1 on BIRC5 alternative splicing was investigated. RESULTS: We show that overexpression of hnRNPA2B1 in GC is correlated with poor survival, and hnRNPA2B1 is required for maintaining GC malignant phenotype by promoting cell proliferation, inhibiting cell apoptosis and increasing cell metastasis. Mechanistically, hnRNPA2B1 co-expressed with several core spliceosome components and controls alternative splicing of anti-apoptotic factor BIRC5. BIRC5 isoform 202 (BIRC5-202) played the oncogenic function in GC cells, and overexpression of the BIRC5-202 transcript partly rescued the decrease in cisplatin resistance induced by downregulation of hnRNPA2B1. CONCLUSIONS: We demonstrate that hnRNPA2B1 regulates BIRC5 splicing and might act as a therapeutic target of chemo-resistant GC cells.

Integrated strategy of LC-MS and network pharmacology for predicting active constituents and pharmacological mechanisms of Ranunculus japonicus Thunb. for treating rheumatoid arthritis.

ETHNOPHARMACOLOGICAL RELEVANCE: Ranunculus japonicus Thunb. (short for R. japonicus) is a topically applied herb with the activities of removing jaundice, nebula and edema, preventing malaria, stopping asthma, promoting diuresis and relieving pain. It was firstly recorded in Zhouhou Beiji Fang and has been used for the treatment of malaria, ulcers, carbuncle, jaundice, migraine, stomachache, toothache and arthritis for over 1800 years. AIM OF THE STUDY: This study aimed to uncover the potentially effective components of R. japonicus and the pharmacological mechanisms against rheumatoid arthritis (RA) by combing LC-MS and network pharmacology. MATERIALS AND METHODS: Firstly, the chemical constituents of R. japonicus were qualitatively identified by UPLC-ESI-LTQ-Orbitrap MS. Then we performed target prediction by PharmMapper, protein-protein interaction (PPI) analysis via String, GO and KEGG pathway enrichment analysis by DAVID and constructed the compound-target-pathway network using Cytoscape. Thirdly, crucial compounds in the network were quantitatively analyzed to achieve quality control of R. japonicus. Finally, the pharmacological activities of R. japonicus and two potentially bioactive ingredients were validated in RA-FLSs (Rheumatoid Arthritis Fibroblast-like Synoviocytes) in vitro. RESULTS: Overall fifty-four ingredients of R. japonicus were identified and forty-five components were firstly discovered in R. japonicus. Among them, twenty-seven validated compounds were predicted to act on twenty-five RA-related targets and they might exhibit therapeutic effects against RA via positive regulation of cell migration, etc. Nine potentially bioactive components of R. japonicus which played important roles in the compound-target-pathway network were simultaneously quantified by an optimized UPLC-ESI-Triple Quad method. In vitro, compared to control group, R. japonicus extract, berberine and yangonin significantly inhibited the migration capacity of RA-FLSs after 24 h treatment. CONCLUSION: This study clarified that R. japonicus and the bioactive ingredients berberine and yangonin might exert therapeutic actions for RA via suppressing the aggressive phenotypes of RA-FLSs through combined LC-MS technology and network pharmacology tools for the first time. The present research provided deeper understanding into the chemical profiling, pharmacological activities and quality control of R. japonicus and offered reference for further scientific research and clinical use of R. japonicus in treating RA.

Integrated UPLC-MS and Network Pharmacology Approach to Explore the Active Components and the Potential Mechanism of Yiqi Huoxue Decoction for Treating Nephrotic Syndrome.

Background: Yiqi Huoxue Decoction (YQHXD) is a traditional Chinese medicine that promotes blood circulation, removes blood stasis, facilitates diuresis, and alleviates edema. It is composed of 10 herbal medicines and has extensive application in treating nephrotic syndrome (NS). However, the active components and the potential mechanism of YQHXD for treating NS remain unclear. Methods: We set up a sensitive and rapid method based on Ultra-High Performance Liquid Chromatograph-Mass (UPLC-MS) to identify the compounds in YQHXD and constituents absorbed into the blood. Disease genes were collected through GeneCards, DisGeNET, and OMIM database. Genes of compounds absorbed into blood were predicted by the TCMSP database. We constructed Disease-Drug-Ingredient-Gene (DDIG) network using Cytoscape, established a Protein-protein interaction (PPI) network using String, Gene biological process (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis was performed using DAVID. Cellular experiments were performed to validate the results of network pharmacology. Result: A total of 233 compounds in YQHXD and 50 constituents absorbed into the blood of rats were identified. The 36 core targets in the PPI network were clustered in the phosphatidylinositol 3 kinase-RAC serine/threonine-protein kinase (PI3K-AKT) and nuclear factor kappa-B (NF-κB) signaling pathways. Luteolin, Wogonin, Formononetin, and Calycosin were top-ranking components as potentially active compounds. Conclusion: The results of our studies show that YQHXD is able to enhance renal function, alleviate podocyte injury, and improve adriamycin nephrotic syndrome.

3-D RoI-Aware U-Net for Accurate and Efficient Colorectal Tumor Segmentation.

Segmentation of colorectal cancerous regions from 3-D magnetic resonance (MR) images is a crucial procedure for radiotherapy. Automatic delineation from 3-D whole volumes is in urgent demand yet very challenging. Drawbacks of existing deep-learning-based methods for this task are two-fold: 1) extensive graphics processing unit (GPU) memory footprint of 3-D tensor limits the trainable volume size, shrinks effective receptive field, and therefore, degrades speed and segmentation performance and 2) in-region segmentation methods supported by region-of-interest (RoI) detection are either blind to global contexts, detail richness compromising, or too expensive for 3-D tasks. To tackle these drawbacks, we propose a novel encoder-decoder-based framework for 3-D whole volume segmentation, referred to as 3-D RoI-aware U-Net (3-D RU-Net). 3-D RU-Net fully utilizes the global contexts covering large effective receptive fields. Specifically, the proposed model consists of a global image encoder for global understanding-based RoI localization, and a local region decoder that operates on pyramid-shaped in-region global features, which is GPU memory efficient and thereby enables training and prediction with large 3-D whole volumes. To facilitate the global-to-local learning procedure and enhance contour detail richness, we designed a dice-based multitask hybrid loss function. The efficiency of the proposed framework enables an extensive model ensemble for further performance gain at acceptable extra computational costs. Over a dataset of 64 T2-weighted MR images, the experimental results of four-fold cross-validation show that our method achieved 75.5% dice similarity coefficient (DSC) in 0.61 s per volume on a GPU, which significantly outperforms competing methods in terms of accuracy and efficiency. The code is publicly available.

A Chromatographic Method for Separation of Tungsten (W) from Silicate Samples for High-Precision Isotope Analysis Using Negative Thermal Ionization Mass Spectrometry.

A new chromatographic method for isolation of W from large masses of silicate samples (>1 g) for ultrahigh precision isotopic analysis was developed. The purification of W was achieved through two stages of rapid chromatographic separations. In the first step, Ti, Zr, Hf, and W were separated collectively from the sample matrix through an AG1-X8 (100-200 mesh) column with a 10 mL resin volume. Subsequently, W was rapidly separated from Ti and Zr-Hf with high purity by a two-step extraction chromatographic method using 0.6 and 0.3 mL TODGA resin columns (50-100 µm particle size), respectively. The total yield of W, including the anion exchange and the TODGA chromatographic separation steps, is greater than 90%. The procedure was employed to isolate W from rock reference materials GSJ JB-3 and USGS BHVO-2; the separated W was analyzed by TRITON Plus TIMS, yielding a 182W/184W of 0.864898 ± 0.000005 (n = 8, 2 SD) for JB-3 and 182W/184W of 0.864896 ± 0.000006 (n = 5, 2 SD) for BHVO-2, which are in agreement with previously reported values within analytical errors.

Crowe Type IV Hip Dysplasia Treated by THA Comebined with Osteotomy to Balance Functional Leg Length Discrepancy: A Prospective Observational Study.

OBJECTIVE: To measure the factors that affect functional leg length of Crowe type IV Developmental dysplasia of the hip (DDH) patients and to review our own methods to balance leg length discrepancy (LLD) in Crowe type IV DDH patients. METHODS: This was a prospective observational study which started in June 2017 and ended in August 2019. Inclusion criteria included: (i) Crowe type I or Crowe type IV hip dysplasia patients who underwent total hip arthroplasty (THA) in the Department of Orthopaedics at our institution between July 2017 and June 2018; (ii) the patients were treated with our specific leg length balance strategy; and (iii) the related outcomes of patients were completely recorded. Finally, 18 consecutive Crowe type I patients (20 hips) and 14 consecutive Crowe type IV patients (18 hips) were selected and divided into two groups according to Crowe types. All patients received THA, and patients with a longer affected side and inferior anatomical acetabular positions in Crowe type IV group also received subtrochanteric osteotomy. During operation and after hip reduction, leg lengths were compared while two legs were in an extended position and the operative leg was on top of the non-operative one. Additional leg length adjustment was applied when leg length was considered to be unequal. Prior to surgery, subluxation height of the femoral head on the affected side, functional LLD, bony length of lower limbs, and distance from teardrops to the lowest point line of the sacroiliac joint were recorded. After surgery, cup sizes, functional LLD, and height of hip rotational centers were measured. Clinical evaluations, such as Harris Hip Score (HHS) and SF-12 scale, were also obtained before and after surgery for all patients. RESULTS: At the last follow-up, functional LLD and clinical measurements of both Crowe type IV group and Crowe type I group were significantly improved. Compared with Crowe type I patients, Crowe type IV patients had a significantly lower MCS, a significantly longer leg lengthening length and a significantly lower hip center height after surgery. Significant differences of tibia length, leg length, and teardrop position were found between affected side and healthy side of Crowe type IV patients. Only three of 14 Crowe type IV patients remained under 1 cm functional LLD. Five patients in the Crowe type IV group developed lower limb numbness immediately following surgery, and they all recovered within 6 months. The average follow-up period for either group was 14 months, and all patients were followed-up at 1, 3, 6, and 12 months then yearly after surgery until the final follow-up. CONCLUSION: After detailed leg length balance process, THA combined with transverse sub-trochanter osteotomy could be an effective method to achieve equal function leg length with most Crowe type IV patients.

hnRNPK promotes gastric tumorigenesis through regulating CD44E alternative splicing.

BACKGROUND: The high prevalence of alternative splicing among genes implies the importance of genomic complexity in regulating normal physiological processes and diseases such as gastric cancer (GC). The standard form of stem cell marker CD44 (CD44S) and its alternatives with additional exons are reported to play important roles in multiple types of tumors, but the regulation mechanism of CD44 alternative splicing is not fully understood. METHODS: Here the expression of hnRNPK was analyzed among the Cancer Genome Atlas (TCGA) cohort of GC. The function of hnRNPK in GC cells was analyzed and its downstream targeted gene was identified by chromatin immunoprecipitation and dual luciferase report assay. Finally, effect of hnRNPK and its downstream splicing regulator on CD44 alternative splicing was investigated. RESULTS: The expression of hnRNPK was significantly increased in GC and its upregulation was associated with tumor stage and metastasis. Loss-of-function studies found that hnRNPK could promote GC cell proliferation, migration, and invasion. The upregulation of hnRNPK activates the expression of the splicing regulator SRSF1 by binding to the first motif upstream the start codon (- 65 to - 77 site), thereby increasing splicing activity and expression of an oncogenic CD44 isoform, CD44E (has additional variant exons 8 to 10, CD44v8-v10). CONCLUSION: These findings revealed the importance of the hnRNPK-SRSF1-CD44E axis in promoting gastric tumorigenesis.

Total Hip Arthroplasty for Crowe Type IV Hip Dysplasia: Surgical Techniques and Postoperative Complications.

Total hip arthroplasty (THA) of Crowe type IV developmental dysplasia of the hip (DDH) is challenging. Although traditional (lateral, posterolateral, and posterior) THA approaches have been used with great anatomic success, they damage periarticular muscles, which are already quite weak in type IV DDH. The recently developed direct anterior approach (DAA) can provide an inter-nerve and inter-muscle approach for THA of type IV dysplasia hips. However, femur exposure with the DAA could be difficult during surgery and it is hard to apply femoral shortening osteotomy. THA techniques used for type IV DDH include anatomic hip center techniques (true acetabular reconstruction) and high hip center techniques, wherein an acetabulum is reconstructed above the original one. Although anatomic construction of the hip center is considered "the gold standard" treatment, it is impossible if the anatomical acetabular is too small and shallow. Procedures used to support type IV DDH reduction with anatomic hip center techniques include greater trochanter osteotomy, lesser trochanter osteotomy, and subtrochanteric osteotomy. However, these techniques have yet to be standardized, and it is unclear which is best for type IV DDH. One-state and two-state non-osteotomy reduction techniques have also been introduced to treat type IV DDH. Potential complications of THA performed in patients with type IV DDH include leg length discrepancy (LLD), peri-operative femur fracture, nonunion of the osteotomy site, and nerve injury. It is worth noting that nowadays an increasing number of Crowe type IV DDH patients are more sensitive to postoperative LLD.

Direct Rubidium-Strontium Dating of Hydrocarbon Charge Using Small Authigenic Illitic Clay Aliquots from the Silurian Bituminous Sandstone in the Tarim Basin, NW China.

Illitic clay is ubiquitous in clastic hydrocarbon reservoirs, and the host for several radiometric isotopes such as the potassium-argon (K-Ar) and rubidium-strontium (Rb-Sr) systems. This study applied the isotope-dilution thermal ionization mass spectrometry technique for small samples (3-4 mg) to conduct illite Rb-Sr isotope dating of five illitic clay samples from the Silurian bituminous sandstone (SBS) intersected by five drillholes in the Tarim Basin, NW China. The 87Rb/86Sr ratio of clays is fractionated mainly by the addition of Rb during the illitization of mixed-layer illite/smectite (I/S), which is the dominant clay species in the Tarim Basin samples. The subsample-scale Rb/Sr isotope values suggest that each subsample may contain I/S particles of slightly variable degrees of illitization. Three of the analyzed samples (H6, KQ1 and TZ67) generated Rb-Sr isochron ages of 141 ± 61 Ma, 332 ± 32 Ma and 235 ± 8 Ma (errors quoted at 2σ), respectively. These results are similar to the corresponding K-Ar ages (125 Ma, 389 Ma and 234 Ma). The isotopic ages are consistent with the timing of hydrocarbon charge which varies in different drillholes as constrained by basin modelling, indicating that a closed-system behavior is attained by the hydrocarbon charge that inhibits the illitization of I/S. The Rb-Sr isotope analyses of the other two samples (YM35-1 and Q1) that did not yield isochron ages suggest the conditions for producing isochrons were not satisfied, which may be caused by disturbance of the isotope system by a post-charge hydrothermal event. The outcomes of this study show the robust potential of Rb-Sr clay subsample geochronology for cross-checking isotopic ages yielded by other systems (e.g. K-Ar system) and constraining the timing of hydrocarbon charge.