A novel surgical approach for en-bloc resection laparoscopic total pancreatectomy

Laparoscopic total pancreatectomy (LTP) is technical challenging and rarely reported in the literature. Herein, we introduced a safe and feasible approach to perform LTP basing on our own experience.Over the period of July 2015 to August 2018, we performed 13 cases of LTP at our institution. Demographic characteristics, intraoperative and postoperative variables, and follow-up outcomes were prospectively collected. The surgical procedures were also described in this study.Seven male and six female patients were included in this study. The median age of the patients was 51 years (range 29-79 years). The median operative time was 355 minutes (range 300-470 minutes). The median estimated blood loss was 200 mL (range 50-1000 mL). The median postoperative hospital stay was 17 days (range 12-23 days). One patient suffered from bile leakage and another patient suffered from delayed gastric emptying. Both patients cured with conservative therapy.Laparoscopic total pancreatectomy can be safely and feasibly performed in well-selected patients.

NWChem: Past, present, and future

Specialized computational chemistry packages have permanently reshaped the landscape of chemical and materials science by providing tools to support and guide experimental efforts and for the prediction of atomistic and electronic properties. In this regard, electronic structure packages have played a special role by using first-principle-driven methodologies to model complex chemical and materials processes. Over the past few decades, the rapid development of computing technologies and the tremendous increase in computational power have offered a unique chance to study complex transformations using sophisticated and predictive many-body techniques that describe correlated behavior of electrons in molecular and condensed phase systems at different levels of theory. In enabling these simulations, novel parallel algorithms have been able to take advantage of computational resources to address the polynomial scaling of electronic structure methods. In this paper, we briefly review the NWChem computational chemistry suite, including its history, design principles, parallel tools, current capabilities, outreach, and outlook.

Facilitating Protein Expression with Portable 5'-UTR Secondary Structures in Bacillus licheniformis

The 5'-untranslated region (5'-UTR) of prokaryotic mRNAs plays an essential role in post-transcriptional regulation. Bacillus species, such as Bacillus subtilis and Bacillus licheniformis, have gained considerable attention as microbial cell factories for the production of various valuable chemicals and industrial proteins. In this work, we developed a portable 5'-UTR sequence for enhanced protein output in the industrial strain B. licheniformis DW2. This sequence contains only ∼30 nt and forms a hairpin structure located right before the open reading frame. The optimized Shine-Dalgarno (SD) sequence was presented as a single strand on the loop of the hairpin for better ribosome recognition and recruitment. By optimizing the free energy of folding, this 5'-element could effectively enhance the expression of eGFP by ∼50-fold and showed good adaptability for other target proteins, including RFP, nattokinase, and keratinase. This 5'-UTR could promote the accessibility of both the SD sequence and start codon, leading to improved efficiency of translation initiation. Furthermore, the hairpin structure protected mRNA against 5'-exonucleases, resulting in enhanced mRNA stability. It is well-known that the stable structure at a ribosome binding site (RBS) impedes initiation in Escherichia coli. In this study, we presented a unique structure at a RBS that can effectively enhance protein production, which is an exception of this prevailing concept. By adjusting a single thermodynamic parameter and holding the other factors affecting protein output constant, a series of 5'-UTR elements with different expression strengths could be rationally designed for wide use in Bacillus sp.

Equation of motion coupled-cluster cumulant approach for intrinsic losses in x-ray spectra

We present a combined equation of motion coupled-cluster cumulant Green's function approach for calculating and understanding intrinsic inelastic losses in core level x-ray absorption spectra (XAS) and x-ray photoemission spectra. The method is based on a factorization of the transition amplitude in the time domain, which leads to a convolution of an effective one-body absorption spectrum and the core-hole spectral function. The spectral function characterizes intrinsic losses in terms of shake-up excitations and satellites using a cumulant representation of the core-hole Green's function that simplifies the interpretation. The one-body spectrum also includes orthogonality corrections that enhance the XAS at the edge.

Successful management of Klippel-Trenaunay syndrome in a pregnant Asian woman: A case report

RATIONALE

Klippel-Trenaunay Syndrome (KTS) is a congenital vascular disease characterized by cutaneous hemangiomas, venous varicosities, and limb hypertrophy. Although extremely rare in pregnant women, the present vascular alterations may be aggravated, consequent to postural and hormonal changes inherent to the pregnancy. Pregnancy is not advised in KTS women due to increased obstetrical risk.

PATIENT CONCERNS

A 31-year-old pregnancy woman presented with prominent vascularity in pelvis, right lower limb, spleen, and liver at 28 weeks of gestation. We started administration of anticoagulant therapy and obstetrics management.

DIAGNOSIS

MRI and ultrasound revealed that multiple varicosities in her pelvis, right lower limb, spleen, and liver. She was diagnosed with KTS.

INTERVENTIONS

At her first visit at 28 weeks of gestation, multidisciplinary evaluation had been done. Blood transfusion and iron supplement had been given for anemia correction. Anticoagulant therapy was performed to prevent potential thrombus risk. She had a vaginal delivery with a healthy newborn in her second visit without any complications at the gestation of 36 weeks due to rupture of preterm membranes.

OUTCOMES

After successful management, the patient was discharged without any complications 2 days after vaginal delivery. No symptoms of hemorrhage or thrombus were observed. At 6 months follow-up, her right lower toes enlarged obviously, MRI revealed that no obvious changes of hemangiomas was found compared to those during the pregnancy and ultrasound revealed that there was no thrombus in her right lower limb.

LESSONS

Patients with KTS can be pregnant and have healthy babies safely with regularly monitor and reasonable treatment during pregnancy. A careful follow-up and guidance are necessary.

Laparoscopic Beger procedure for the treatment of chronic pancreatitis: a single-centre first experience

Background

The Beger procedure is a common surgical option in the management of the unremitting abdominal pain of chronic pancreatitis (CP). As an organ-sparing surgery, it might be a better choice than pancreatoduodenectomy (PD). However, it is rather challenging for surgeons to perform the Beger procedure laparoscopically, especially for patients with CP; indeed, it has rarely reported. Here, we describe the technique and results of our early experience in laparoscopic Beger procedure for the treatment of CP.

Case presentation

Five patients (1 male) with CP (alcohol induced, n = 3; idiopathic, n = 2) who underwent laparoscopic Beger procedure from May to October 2019 in West China Hospital were included in this study. The median pancreatic duct diameter was 6.8 (4 to 12) mm. The median operating time was 275 (150 to 305) minutes without conversion. Only one patient (20%) developed a grade B pancreatic fistula. One patient required re-operation for jejunal anastomotic bleeding on the first post-operative day. The median hospital stay was 11 (9 to 34) days. No patient experienced biliary fistula, gastroparesis, duodenal necrosis, or abdominal bleeding. The 90-day mortality rate was 0%. All the patients were pain free in the two months after the operation.

Conclusion

The laparoscopic Beger procedure is feasible and safe with good short-term results and some potential benefits in selected patients with chronic pancreatitis. Further study and longer follow-up are required.

LipidCreator workbench to probe the lipidomic landscape

Mass spectrometry (MS)-based targeted lipidomics enables the robust quantification of selected lipids under various biological conditions but comprehensive software tools to support such analyses are lacking. Here we present LipidCreator, a software that fully supports targeted lipidomics assay development. LipidCreator offers a comprehensive framework to compute MS/MS fragment masses for over 60 lipid classes. LipidCreator provides all functionalities needed to define fragments, manage stable isotope labeling, optimize collision energy and generate in silico spectral libraries. We validate LipidCreator assays computationally and analytically and prove that it is capable to generate large targeted experiments to analyze blood and to dissect lipid-signaling pathways such as in human platelets.

Indocyanine Green-Enhanced Fluorescence in Laparoscopic Duodenum-Preserving Pancreatic Head Resection: Technique with Video

BACKGROUND

In 1972, Beger et al.1 first described duodenum-preserving pancreatic head resection (DPPHR) for patients with severe chronic pancreatitis. Then DPPHR also was proved capable of providing comparable long-term oncologic outcomes in the setting of benign or low-grade malignant tumors.2 As an organ-preserving procedure, DPPHR preserves the integrity of the digestive tract and improves the patient's quality of life compared with pancreaticoduodenectomy (PD),3 although DPPHR is more technically challenging, especially in protecting the bile duct and the pancreaticoduodenal vascular arch.4^,5 The indocyanine green (ICG)-enhanced fluorescence imaging system in laparoscopic surgery can identify the biliary and vascular anatomy clearly to ensure a safe cholecystectomy and an adequate vascular supply for colectomy or nephrectomy.6 Nevertheless, to date, no report has described ICG-enhanced fluorescence in laparoscopic duodenum-preserving pancreatic head resection (LDPPHR). This article describes the technique of LDPPHR using a video of a real-time ICG fluorescence imaging system.

METHODS

A 29-year-old woman received a diagnosis of chronic pancreatitis and an inflammatory mass in the head of the pancreas. A computed tomography (CT) scan showed atrophy of the pancreas, dilation of the main pancreatic duct, and heterogeneous enhancement of the pancreatic head parenchyma (Fig. 1). Her other preoperative examination results were normal except for high blood sugar. To avoid an extended PD for this young patient, LDPPHR was performed. The patient was placed in supine position with her two legs apart. The observing trocar (10 mm) was located at the inferior umbilicus. Four trocars (two 5-mm trocars and two 12-mm trocars) were distributed symmetrically at the midclavicular line and anterior axillary line. Another 5-mm trocar located at the subxiphoid was used for traction of the stomach with a rubber band. Before the operation, ICG (5 mg) was injected intravenously from the elbow vein. The gastrocolic ligament was opened, and the hepatic flexure of the colon was taken down to explore the head of the pancreas without making a Kocher's maneuver. After hanging of the distal stomach with a rubber band, both the right gastroepiploic vein and Henle's trunk were dissected. The number 8a lymph node was dissected for intraoperative rapid frozen pathology. A post-pancreatic neck tunnel was built, and the pancreatic neck was transected with an ultrasonic scalpel. The main pancreatic duct was identified and transected with cold scissors. The superior mesenteric vein (SMV) was hung with another rubber band and retracted to the left. The uncinate process of the pancreas was retracted to the right, and subcapsular dissection was performed, with particular attention paid to protection of the anterior inferior pancreaticoduodenal artery (AIPDA), the posterior inferior pancreaticoduodenal artery (PIPDA), and their branches that go into the duodenum. Then the gastroduodenal artery (GDA) was identified, and the anterosuperior pancreatic duodenal artery (ASPDA) was dissected. The upper part of the pancreatic head was separated to expose the common bile duct (CBD) with the help of real-time ICG fluorescence imaging (Fig. 2). The pancreas was dissected from the left edge of the duodenum and the right and ventral edges of the CBD. The posterosuperior pancreatic duodenal artery (PSPDA) was identified at the dorsal edge of the CBD. The PSPDA and its branches going into the distal CBD as well as the ampulla of Vater were carefully preserved. The proximal side of the main and accessory pancreatic duct was identified and sutured. Pancreatic anastomosis was performed using the technique of Bing's anastomosis.7 Fig. 1 Enhanced computed tomography (CT) scan showing atrophy of the pancreas, dilatation of the main pancreatic duct, and heterogeneous enhancement of the pancreatic head parenchyma Fig. 2 The common bile duct was separated and exposed from the head to the tail by the assistance of the real-time indocyanine green (ICG)-enhanced fluorescence imaging system RESULTS: The operation time was 251 min, and the estimated blood loss was 150 ml. The postoperative course was uneventful, with a hospital stay of 13 days. From February 2019 to November 2019, LDPPHR was used by the authors to manage 24 cases, including chronic pancreatitis (6 cases), pancreatic intraductal papillary mucinous tumors (6 cases), pancreatic neuroendocrine tumors (4 cases), pancreatic solid pseudopapillary tumors (4 cases), serous cystadenoma (3 cases), and mucinous cystadenoma (1 case).

CONCLUSIONS

Indocyanine green-enhanced fluorescence in laparoscopic duodenum-preserving pancreatic head resection was safe and may offer a benefit for maintaining the integrity of the biliary system.

[Application of Early Splenic Artery Occlusion in Laparoscopic Spleen-preserving Distal Pancreatectomy using Kimura Technique]

Objective

To present our institutional experience in laparoscopic spleen-preserving distal pancreatectomy (Lap-SPDP) using Kimura technique with or without early occlusion of the root of the splenic artery. In addition, to explore the safety and feasibility of this occlusion technique, especially its advantages in intraoperative hemorrhage control and spleen preservation.

Methods

From February 2011 to May 2019, 54 consecutive patients who were diagnosed as benign or low-grade malignant space-occupying lesions at the body and the tail of pancreas underwent Lap-SPDP using Kimura technique in our institution. Twenty-five patients before 2015 were allocated into non-occlusion group and 29 patients after 2015 were allocated into occlusion group. The non-occlusion group underwent direct dissection of the distal pancreas with blood supply from the splenic artery as well as traditional traction of the splenic artery without occlusion. Whereas the occlusion group underwent temporary occlusion of the root of the splenic artery by Bulldog clip after transecting the neck of the pancreas and distal pancreas was excised under a relatively bloodless situation. Surgical techniques were described in detail. Data between groups were retrospectively collected and stratification analysis was performed based on the diameter of tumor (>3 cm or ≤3 cm).

Results

Before stratification, there was a statistical difference in age between the two groups ( P=0.033), but no difference in body mass index (BMI) ( P=0.069). The median lesion diameter of the two groups was 2.5 cm and 4 cm, respectively, with no statistical difference ( P=0.065). The success rates of spleen preservation in the two groups were 93.1% and 92% respectively, showing no significant difference ( P=1.000). The length of hospital stay was slightly longer in the non-occlusion group than that in the occlusion group ( P=0.020). Comparing with the non-occlusion group, the occlusion group had significantly shorter operation time (median, 165 min vs. 235 min) and less estimated blood loss (median, 100 mL vs. 200 mL) ( P<0.05). After stratification by the tumor diameter, there were 2 cases of failed spleen preservation both in occlusion and non-occlusion group with tumor diameter >3 cm (occlusion group: 2/8, 25% and non-occlusion group: 2/14,14.3%). However there was no statistical difference between the two groups ( P=0.602). When the tumor diameter ≤3 cm, the spleen preservation rate of both groups reached 100%. When the tumor diameter was >3 cm, the operation time of the occlusion group was shorter than that of the non-occlusion group ( P=0.005). In terms of intraoperative blood loss, regardless of tumor size, the occlusion group had less estimated blood loss than that of the non-occlusion group ( P<0.05). In the occlusion group, no conversion or blood transfusion was needed intraoperatively and/or postoperatively. After stratification, there was no difference in the length of hospital stay between two groups ( P>0.05). During the follow-up period (median (Min-Max), 13.5 (3-96) months), no perioperative death, disease recurrence, portal vein or splenic vein thrombosis, gastric varices or upper gastrointestinal bleeding was noted.

Conclusion

Lap-SPDP using Kimura technique with early occlusion of the root of splenic artery was safe and feasible and could be generally applied. By using this technique, we could reduce the operation time and blood loss, as well as sustain a high probability of spleen preservation.

Genomic Features of Cladobotryum dendroides, Which Causes Cobweb Disease in Edible Mushrooms, and Identification of Genes Related to Pathogenicity and Mycoparasitism

Cladobotryum dendroides, which causes cobweb disease in edible mushrooms, is one of the major fungal pathogens. Our previous studies focused on the genetic and morphological characterization of this fungus, as well as its pathogenicity and the identification of appropriate fungicides. However, little is known about the genome characters, pathogenic genes, and molecular pathogenic mechanisms of C. dendroides. Herein, we reported a high-quality de novo genomic sequence of C. dendroides and compared it with closely-related fungi. The assembled C. dendroides genome was 36.69 Mb, consisting of eight contigs, with an N50 of 4.76 Mb. This genome was similar in size to that of C. protrusum, and shared highly conserved syntenic blocks and a few inversions with C. protrusum. Phylogenetic analysis revealed that, within the Hypocreaceae, Cladobotryum was closer to Mycogone than to Trichoderma, which is consistent with phenotypic evidence. A significant number of the predicted expanded gene families were strongly associated with pathogenicity, virulence, and adaptation. Our findings will be instrumental for the understanding of fungi-fungi interactions, and for exploring efficient management strategies to control cobweb disease.

Resistance Profiles of Salmonella Isolates Exposed to Stresses and the Expression of Small Non-coding RNAs

Salmonella can resist various stresses and survive during food processing, storage, and distribution, resulting in potential health risks to consumers. Therefore, evaluation of bacterial survival profiles under various environmental stresses is necessary. In this study, the resistance profiles of five Salmonella isolates [serotypes with Agona, Infantis, Typhimurium, Enteritidis, and a standard strain (ATCC 13076, Enteritidis serotype)] to acidic, hyperosmotic, and oxidative stresses were examined, and the relative expressions of non-coding small RNAs were also evaluated, including CyaR, MicC, MicA, InvR, RybB, and DsrA, induced by specific stresses. The results indicated that although all tested strains displayed a certain resistance to stresses, there was great diversity in stress resistance among the strains. According to the reduction numbers of cells exposed to stress for 3 h, S. Enteritidis showed the highest resistance to acidic and hyperosmotic stresses, whereas ATCC 13076 showed the greatest resistance to oxidative stress, with less than 0.1 Log CFU/ml of cell reduction. Greater resistance of cells to acidic, hyperosmotic, and oxidative stresses was observed within 1 h, after 2 h, and from 1 to 2 h, respectively. The relative expression of sRNAs depended on the isolate for each stress; acidic exposure for the tested isolates induced high expression levels of DsrA, MicC, InvR, RybB, MicA, and CyaR. The sRNA RybB, associated with sigma E and outer membrane protein in bacteria, showed a fold change of greater than 7 in S. Enteritidis exposed to the tested stresses. CyaR and InvR involved in general stress responses and stress adaptation were also induced to show high expression levels of Salmonella exposed to hyperosmotic stress. Overall, these findings demonstrated that the behaviors of Salmonella under specific stresses varied according to strain and were likely not related to other profiles. The finding also provided insights into the survival of Salmonella subjected to short-term stresses and for controlling Salmonella in the food industry.

Laparoscopic partial splenectomy with temporary occlusion of the trunk of the splenic artery in fifty-one cases: experience at a single center

BACKGROUND

Laparoscopic partial splenectomy (LPS) for splenic benign space-occupying lesions has been reported by many researchers; however, few studies have described methods to control intraoperative bleeding. Trustworthy experience in LPS with a satisfactory intraoperative hemorrhage control technique is therefore necessary. The current study aims to present our experience in LPS with temporary occlusion of the trunk of the splenic artery for controlling intraoperative bleeding with a large sample of 51 cases and to evaluate the safety, feasibility, and reproducibility of this technique.

METHODS

Fifty-one patients from August 2014 to April 2019 who underwent LPS in our institution were retrospectively analyzed. Surgical techniques were described in detail.

RESULTS

All patients had successfully undergone LPS with temporary occlusion of the trunk of the splenic artery. Conversions to open surgery, hand-assisted laparoscopic splenectomies, or blood transfusions were not needed. The operative time was 94.75 ± 18.91 min, the estimated blood loss was 71.13 ± 53.87 ml, and the volume of resected spleen was 34.75 ± 12.19%. The range of postoperative stays was 4-14 days. One female patient (2%, 1/51) suffered from postoperative complications. No perioperative mortality, incision infections, postoperative pancreatic fistulas (POPFs), splenic infarctions, or portal/splenic vein thromboembolic events occurred.

CONCLUSION

LPS is an effective spleen-preserving surgery. Although there are many other bleeding control methods, temporarily occluding the trunk of the splenic artery was found to be a safe, feasible, and reproducible technique in LPS. The outcomes of this technique and the efficacy of splenic parenchyma preservation are acceptable.

MicroRNA-107 may regulate lung cancer cell proliferation and apoptosis by targeting TP53 regulated inhibitor of apoptosis 1

Lung cancer causes over 1.6 million mortalities worldwide annually. MicroRNAs (miRs) are involved in various types of cancer-associated processes. The present study investigated the possible mechanism of miR-107 in the development of lung cancer in order to identify novel targets for clinical treatment. The expression levels of miR-107 and its putative target gene TP53 regulated inhibitor of apoptosis 1 (TRIAP1) were measured in lung cancer tumor tissues and non-tumor adjacent tissues. Subsequently, the association between TRIAP1 and miR-107 was investigated using a dual-luciferase reporter assay. Following transfection, the effects of miR-107 and TRIAP1 on the proliferation and apoptosis of lung cancer cell lines in vitro were investigated using Cell Counting Kit-8 and flow cytometry assays, respectively. Furthermore, the regulatory effect of miR-107 on the expression levels of TRIAP1 and associated proteins was analyzed using a western blot assay. The results revealed lower expression levels of miR-107 and higher expression levels of TRIAP1 in lung cancer tumor tissues compared with non-tumor adjacent tissues. The dual-luciferase reporter assay demonstrated that TRIAP1 is a target gene of miR-107. Additionally, the results revealed that overexpression of miR-107 resulted in a lower proliferation rate and higher apoptosis rate of A549 cells, compared with the negative control (NC) and control groups (P<0.01). The variation of cell proliferation and apoptosis induced by miR-107 mimics was reversed by co-transfection with pcDNA3.1-TRIAP1. Furthermore, the expression levels of cyclin D1 and proliferating cell nuclear antigen were markedly decreased in the miR-107 mimics group compared with the NC group (P<0.01). The expression levels of BCL2 associated X apoptosis regulator, tumor protein p53 and caspase 3 were upregulated and the expression levels of TRIAP1 and BCL2 apoptosis regulator were significantly reduced in the miR-107 mimics group compared with the NC group (P<0.01). The results of the present study suggested that miR-107 regulates lung cancer cell proliferation and apoptosis by targeting TRIAP1.

Effects of Cu2+ incorporation on ZnAl-layered double hydroxide

The incorporation of copper affects the particle size of LDHs and the coordination number of aluminum.

The association between GSTP1 polymorphism and pre-eclampsia risk: a system review and meta-analysis

PURPOSE

Oxidative stress is thought to play an important role in the pathophysiology of pre-eclampsia. Polymorphism of Glutathione S-transferase P1 (GSTP1) protect cells against the cytotoxic effects of reactive compounds. Published data on the association between the GSTP1 polymorphism and pre-eclampsia risk are controversial. A meta-analysis was performed to assess whether the polymorphisms of GSTP1 are associated with pre-eclampsia risk.

METHODS

Medline, Embase, China National Knowledge Infrastructure, and Chinese Biomedicine Databases were searched to identify eligible studies. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) for GSTP1 polymorphism and pre-eclampsia were appropriately derived from fixed-effects or random effects models.

RESULTS

A total of six studies were enrolled in this meta-analysis. The pooled analyses revealed that GSTP1 polymorphism was not associated with pre-eclampsia risk. Heterogeneity among studies was founded in allele contrast. Galbraith plot analyses were performed to assess the source of heterogeneity and one study was found to be contributor of heterogeneity. The heterogeneity decreased significantly after excluding that study.

CONCLUSION

Present meta-analysis demonstrates that GSTP1 polymorphism may be not correlated with pre-eclampsia risk.

Autophagy triggered by MAVS inhibits Coxsackievirus A16 replication

Mitochondrial antiviral signaling protein (MAVS), a crucial adaptor protein localized on mitochondria, plays vital roles in various biological processes. Autophagy and apoptosis are two independent and closely linked cell death pathways. But whether MAVS could induce apoptosis and autophagy in rhabdomyosarcoma cells (RD cells) and what is the relationship between autophagy and apoptosis still remains elusive. Here, we reveal that overexpression of MAVS could trigger both apoptosis and autophagy in RD cells. Interestingly, MAVS-induced apoptosis was dependent on the activation of the c-Jun N-terminal kinase (JNK) signaling pathway and inhibition of the extracellular signal-regulated kinase (ERK) signaling pathway. Also, it was found that inhibition of autophagy by 3-methyladenine (3-MA) enhanced MAVS-induced apoptosis resulting in increased cleavage of caspase-3 and poly (ADP-ribose) polymerase (PARP). Meanwhile, autophagy induction by rapamycin resulted in decreased MAVS-induced apoptosis. In addition, we found that MAVS expression was inhibited upon Coxsackievirus A16 (CA16) infection and overexpression of MAVS could inhibit CA16 replication. Collectively, our study provides novel insights into the link between apoptosis and autophagy induced by MAVS overexpression in RD cells and gains a greater understanding of MAVS-induced antiviral functions, which provide new targets for CA16 treatment. Keywords: CA16; MAVS; apoptosis; autophagy.

Streamlined MRM method transfer between instruments assisted with HRMS matching and retention-time prediction

Multiple reaction monitoring (MRM) mode using liquid-chromatography tandem mass spectrometry (e.g., LC-QqQ-MS/MS) has been extensively employed in the small molecule analysis with trace levels in complex samples owing to its high sensitivity. However, most of the reported MRM methods are developed using authentic standards, which are often costly yet not readily available. To address this question, a practical platform for the MRM method transfer between different LC-QqQ-MS/MS instruments, assisted by the high-resolution mass spectrometry (LC-HRMS) and retention time (RT) prediction, has been developed in this study. The reported platform can take advantage of both the high sensitivity of LC-MRM method and ion transition pairs from the previous publications. LC-HRMS can provide the accurate mass measurement of the compounds, though high-quality MS/MS fragments are usually difficult to obtain for chemicals at trace levels. Retention time matching and peaks matching between both instrumental platforms rule out isobaric candidates. With an additional retention time prediction filter from quantitative structure retention relationship (QSRR) model based on random forest feature selection (Pearson r² = 0.63), identification of small molecules is achieved at a high confidence level without using authentic standards. The developed platform has been validated with robustness by examining spiked environmental chemicals in sludge water samples, biological urine, and cell extracts.

Alashanoids K-M, bioactive eremophilane sesquiterpenoids from Syringa pinnatifolia

Three new eremophilane-type sesquiterpenoids, alashanoids K-M (1-3), and one known analogue (4) were isolated from the peeled stems of Syringa pinnatifolia. All the compounds were isolated from the genus Syringa for the first time. Structures of these compounds were established using 1D and 2D NMR and MS data. The absolute configurations were determined by experimental and calculated electronic circular dichroism analysis, a modification of Mosher's method, and X-ray diffraction. Compounds 2 and 3 inhibited NO production in LPS-induced RAW264.7 macrophage cells with IC₅₀ values of 14.23 and 12.20 μM, respectively, and showed cytotoxic activities against HepG2 cells with the IC₅₀ values of 34.41 and 40.86 μM, respectively.