Clinical Effect of Ultrasound-Guided Adductor Block on Postoperative Analgesia After Total Knee Replacement.

Objective: To explore the clinical effects of ultrasound-guided adductor block (UGAB) on postoperative analgesia after total knee replacement. Methods: From March 2022 to June 2022, 60 patients in the First Affiliated Hospital of Chongqing Medical University were included. They were divided into control (n = 30) and ultrasonic groups (n = 30). They all received total knee arthroplasty. Before total knee arthroplasty, patients in the control and ultrasonic groups underwent general anesthesia and UGAB, respectively. Visual Analogue Scale (VAS) was used to assess the pain. The time of the first straight leg elevation and the first landing time were recorded. Knee joint function was evaluated. Information about the dosage of tramadol intramuscular injection and the number of times patient-controlled analgesia pump pressing was collected. The serum levels of interleukin-6 (IL-6) and high-sensitivity C-reactive protein (hs-CRP) were detected. Results: Compared with the control group, UGAB increased the rate of muscle contraction and relaxation and total and relaxation after total knee replacement in the ultrasonic group (P < .05). UGAB reduced VAS scores of pain during passive activity after operation (P < .05). UGAB also facilitated the first straight leg lifting time after the operation and the time of the first landing after the operation (P < .05). Meanwhile, UGAB reduced the dose of tramadol and press times of the self-control analgesia pump after operation (P < 0.05). UGAB also suppressed postoperative IL-6 and hs-CRP levels and increased postoperative joint range of motion (P < .05). Conclusion: UGAB promotes early recovery of knee function with high safety in patients undergoing total knee replacement, with reduced postoperative pain and inflammatory reaction.

Detecting tea tree pests in complex backgrounds using a hybrid architecture guided by transformers and multi-scale attention mechanism.

BACKGROUND: Tea pests pose a significant threat to tea leaf yield and quality, necessitating fast and accurate detection methods to improve pest control efficiency and reduce economic losses for tea farmers. However, in real tea gardens, some tea pests are small in size and easily camouflaged by complex backgrounds, making it challenging for farmers to promptly and accurately identify them. RESULTS: To address this issue, we propose a real-time detection method based on TP-YOLOX for monitoring tea pests in complex backgrounds. Our approach incorporates the CSBLayer module, which combines convolution and multi-head self-attention mechanisms, to capture global contextual information from images and expand the network's perception field. Additionally, we integrate an efficient multi-scale attention module to enhance the model's ability to perceive fine details in small targets. To expedite model convergence and improve the precision of target localization, we employ the SIOU loss function as the bounding box regression function. Experimental results demonstrate that TP-YOLOX achieves a significant performance improvement with a relatively small additional computational cost (0.98 floating-point operations), resulting in a 4.50% increase in mean average precision (mAP) compared to the original YOLOX-s. When compared with existing object detection algorithms, TP-YOLOX outperforms them in terms of mAP performance. Moreover, the proposed method achieves a frame rate of 82.66 frames per second, meeting real-time requirements. CONCLUSION: TP-YOLOX emerges as a proficient solution, capable of accurately and swiftly identifying tea pests amidst the complex backgrounds of tea gardens. This contribution not only offers valuable insights for tea pest monitoring but also serves as a reference for achieving precise pest control. © 2023 Society of Chemical Industry.

Set of Cytochrome P450s Cooperatively Catalyzes the Synthesis of a Highly Oxidized and Rearranged Diterpene-Class Sordarinane Architecture.

Cytochrome P450s are one of the most versatile oxidases that catalyze significant and unique chemical transformations for the construction of complex structural frameworks during natural product biosynthesis. Here, we discovered a set of P450s, including SdnB, SdnH, SdnF, and SdnE, that cooperatively catalyzes the reshaping of the inert cycloaraneosene framework to form a highly oxidized and rearranged sordarinane architecture. Among them, SdnB is confirmed to be the first P450 (or oxidase) that cleaves the C-C bond of the epoxy residue to yield formyl groups in pairs. SdnF selectively oxidizes one generated formyl group to a carboxyl group and accelerates the final Diels-Alder cyclization to furnish the sordarinane architecture. Our work greatly enriches the enzyme functions of the P450 superfamily, supplies the missing skills of the P450 synthetic toolbox, and supports them as biocatalysts in further applications toward the synthesis of new chemical entities.

Focal points of preanesthesia evaluations for electroconvulsive therapy in patients with depression: a retrospective analysis of clinical characteristics in nonremission.

BACKGROUND: This study explored the patient clinical characteristics that may affect electroconvulsive therapy (ECT) efficacy to enable improved focus during evaluations and preparation for ECT. METHODS: Patients were enrolled for ECT at the Department of Psychiatry and Anesthesiology of the First Affiliated Hospital of Chongqing Medical University from December 2017 to January 2019. The primary outcome in our study was defined as the development of nonremission. A multivariate logistic analysis was performed to identify the risk factors for nonremission. RESULTS: In total, 874 depressed patients were included in the study. After the ECT treatment, 255 cases (29.2%) exhibited nonremission. A multivariate logistic regression analysis of the variables was performed, and the results showed that atherosclerosis (OR 8.072, 95% CI 2.442 to 16.675; P = 0.001), COPD (OR 2.919, 95% CI 1.240 to 6.871; P = 0.014), diabetes (OR 2.202, 95% CI 1.115 to 4.348; P = 0.023) and smoking (OR 1.519, 95% CI 1.015 to 2.273; P = 0.042) were independent risk factors for nonremission. CONCLUSION: In the retrospective analysis, we found that atherosclerosis, diabetes, COPD and smoking may be high-risk factors for nonremission.

Parecoxib ameliorates renal toxicity and injury in sepsis-induced mouse model and LPS-induced HK-2 cells.

Parecoxib is a selective COX-2-specific inhibitor, which has been demonstrated to inhibit sepsis-induced systemic inflammation, but its role in sepsis-induced acute kidney injury has not been studied. This study was designed to investigate the effects of Parecoxib on sepsis-induced acute kidney injury. In this study, the mice sepsis model was established using an internationally recognized cecal ligation and puncture (CLP). Hematoxylin-eosin staining was performed to examine kidney injury. Biochemical kit was used to detect the expression of BUN and Cre in serum, and ELISA was used to detect the expression of inflammatory factors in renal tissue. Tunel staining was used to detect tissue apoptosis. Furthermore, CCK-8 assay was used to detect the cell viability of HK-2 cells and RT-qPCR was used to detect the expression of LPS-induced inflammatory factors in HK-2 cells.TUNEL staining was used to detect the level of cell apoptosis. Finally, the expressions of COX-2, p-NF-kB P65, p-IKKß, NF-kB P65, IKKß, Kim1, NGAL, iNOS, VEGF, VEGFR2, CD31 and apoptosis-related proteins in renal tissues and HK-2 cells were detected by Western blot. We discovered that parecoxib could alleviate renal pathological changes, reduce renal function injury, and inhibit renal pathology to inhibit the release of inflammatory factors in renal tissue. Parecoxib inhibited sepsis induced microvascular damage and apoptosis in renal tissue. Parecoxib reduced the inflammation and apoptosis of renal tubular epithelial cells induced by LPS. Our data suggest that Parecoxib ameliorates sepsis-induced kidney injury, and may have potential as a novel therapeutic method for treating sepsis-induced kidney injury.

Enhanced Insecticidal Effect and Interface Behavior of Nicotine Hydrochloride Solution by a Vesicle Surfactant.

Nicotine hydrochloride (NCT) has a good control effect on hemiptera pests, but its poor interfacial behavior on the hydrophobic leaf leads to few practical applications. In this study, a vesicle solution by the eco-friendly surfactant, sodium diisooctyl succinate sulfonate (AOT), was prepared as the pesticide carrier for NCT. The physical chemical properties of NCT-loaded AOT vesicles (NCT/AOT) were investigated by techniques such as dynamic light scattering (DLS), small-angle X-ray scattering (SAXS), and cryogenic transmission electron microscopy (cryo-TEM). The results showed that the pesticide loading and encapsulation efficiency of NCT/AOT were 10.6% and 94.8%, respectively. The size of NCT/AOT vesicle was about 177 nm. SAXS and surface tension results indicated that the structure of the NCT/AOT vesicle still existed with low surface tension even after being diluted 200 times. The contact angle of NCT/AOT was always below 30°, which means it could wet the surface of the cabbage leaf well. Consequently, NCT/AOT vesicles could effectively reduce the bounce of pesticide droplets. In vitro release experiments showed that NCT/AOT vesicles had sustained release properties; 60% of NCT in NCT/AOT released after 24 h, and 80% after 48 h. Insecticidal activity assays against aphids revealed that AOT vesicles exhibited insecticidal activity and could have a synergistic insecticidal effect with NCT after the loading of NCT. Thus, the NCT/AOT vesicles significantly improved the insecticidal efficiency of NCT, which has potential application in agricultural production activities.

Prevalence and predictors of chronic postsurgical pain after colorectal surgery: A prospective study.

AIM: The aim was to investigate the incidence, characteristics and the potential predictors of chronic postsurgical pain (CPSP) after colorectal surgery. METHOD: Patients who underwent colorectal surgery at our institution from July 2014 to December 2016 were prospectively enrolled in this study. Perioperative potential demographic, clinical and psychological predictors for CPSP were collected. The follow-up visits were conducted through telephone interviews at 3 and 6 months postoperatively. The interview questionnaire comprised items regarding pain intensity, frequency, site, analgesic administration and impact on activities of daily living. RESULTS: A total of 624 patients completed the 6-month follow-up and were included in the analysis. CPSP was reported by 32.1% of these patients at 3 months and 21.8% at 6 months after colorectal surgery. The pain interfered with several activities of daily living in a considerable proportion of CPSP cases. At 3 months, the identified predictors of CPSP were young age, preoperative abdominal pain and pain elsewhere, preoperative anxiety and depression, longer duration of surgery, and high pain intensity on movement within 24 h after surgery. Predictors of CPSP at 6 months were young age, preoperative abdominal pain, preoperative anxiety, longer duration of surgery, and high pain intensity on movement within 24 h after surgery. CONCLUSION: Chronic pain after colorectal surgery is a common complication associated with young age, preoperative abdominal pain and pain elsewhere, preoperative anxiety and depression, longer duration of surgery, and high pain intensity on movement within 24 h after surgery.

Enantioseparation processes and mechanisms in functionalized graphene membranes: Facilitated or retarded transport?

Up to date, functionalized graphene-based membranes have exhibited a promising potential in the enantioseparation. However, since precisely controlling the interlayer distance of two-dimensional materials is a great challenge in practical experiments, the transport mechanism of chiral guests in such membranes, together with various critical parameters that play a controlling role in the transport behaviors of the preferentially binding enantiomer in narrow channels, remains to be explored. The molecular dynamics (MD) simulation, especially using the steered MD (SMD) method, might be an alternative way to investigate the enantioseparation processes and mechanisms of layered membranes with different interlayer distances. In this work, D-alanine modified graphene sheets with different interlayer distances were built as membrane models, whereas D- and L-phenylalanine were selected as chiral probes. The effect of the interlayer distance and the applied external force on the enantioseparation performance was examined. Results show that such two parameters exert a significant influence on the enantioseparation performance: (a) Increasing the interlayer distance would result in a conversion from the retarded to the facilitated mechanism at a proper external force (medium); (b) both the large and small driving forces would only lead to the appearance of the retarded transport for the preferential enantiomer, unlike the moderate force; (c) the interaction energy of L-phenylalanine with D-isomer selector decreases with the rising interlayer distances studied in this work, regardless of what the external force is. Our findings can provide guidance on the practical applications in the membrane-based chiral separation.

Effects of Low-Dose Ketamine on the Antidepressant Efficacy and Suicidal Ideations in Patients Undergoing Electroconvulsive Therapy.

OBJECTIVES: It remains controversial whether a subanesthetic dose of ketamine could modulate the antidepressant effect of electroconvulsive therapy (ECT) in patients with major depressive disorder. We investigated the effect of ketamine on accelerating the antidepressant efficacy of ECT. METHODS: One hundred twenty-seven patients with major depressive disorder were included in this randomized, placebo-controlled, double-blind study. The study group received 0.3 mg/kg ketamine, and the control group received an isovolumetric dose of normal saline before undergoing ECT under propofol anesthesia. The main outcome was the Hamilton Depression Rating Scale score after each ECT session. Suicidal ideation (SI) was also evaluated using the Hamilton Depression Rating Scale. The response, remission, and recurrence rates were analyzed using time-to-event analysis. RESULTS: No significant differences were found in the overall response, remission, and relapse rates between the groups (P > 0.05). The median number of ECT sessions for achieving response was 4.0 ± 0.41 in the study group and 7.0 ± 0.79 in the control group (P < 0.05). The median number of ECT sessions for achieving remission in the study and control groups was 8.0 ± 0.29 and 9.0 ± 0.48, respectively (P < 0.05). The median number of ECT sessions for achieving SI reduction in the study and control groups was 3.0 ± 0.75 and 6.0 ± 1.19, respectively (P < 0.05). CONCLUSIONS: Low-dose ketamine (0.3 mg/kg) could modulate the antidepressant efficacy of ECT via accelerating the onset of its effects and reducing the number of ECT sessions required to obtain response, remission, and SI reduction, without influencing the relapse rates in remitting patients after ECT treatment.

Enzymatic Intermolecular Hetero-Diels-Alder Reaction in the Biosynthesis of Tropolonic Sesquiterpenes.

Diels-Alder reactions are among the most powerful synthetic transformations to construct complex natural products. Despite that increasing of enzymatic intramolecular Diels-Alder reactions have been discovered, natural intermolecular Diels-Alderases are rarely described. Here, we report an intermolecular hetero-Diels-Alder reaction in the biosynthesis of tropolonic sesquiterpenes and functionally characterize EupfF as the first fungal intermolecular hetero-Diels-Alderase. We demonstrate that EupfF catalyzed the dehydration of a hydroxymethyl-containing tropolone (5) to generate a reactive tropolone o-quinone methide (6) and might further stereoselectively control the subsequent intermolecular hetero-Diels-Alder reaction with (1E,4E,8Z)-humulenol (8) to produce enantiomerically pure neosetophomone B (1). Our results reveal the biosynthetic pathway of 1 and expand the repertoire of activities of Diels-Alder cyclases.

MicroRNA-193a Downregulates HMGB1 to Alleviate Diabetic Neuropathic Pain in a Mouse Model.

BACKGROUND: Diabetic neuropathy is a serious complication for diabetic patients involving the nervous system. This disease is a quiet but painful condition caused by chronically high blood glucose levels. It is reported that high mobility group box 1 protein (HMGB1) participates in the development of neuropathic pain. This study aimed to explore the role of microRNA (miR)-193a in diabetic neuropathic pain through the regulation of HMGB1. METHODS: A diabetic mouse model was established through the injection of streptozocin (STZ). Neuropathic pain development was shown by paw withdrawal thresholds and paw withdrawal latency. Expression levels of relative genes or miR were analyzed by qRT-PCR, while Western blot was employed to assess the protein levels. The interaction between miR-193a and HMGB1 mRNA 3'-UTR region was shown by luciferase assay. The levels of inflammation cytokines were measured by ELISA kits. RESULTS: miR-193a expression was decreased and HMGB1 expression was upregulated in the lumbar spinal dorsal horn of STZ-induced diabetic mice. miR-193a inhibited HMGB1 expression in the lumbar spinal dorsal horn. Overexpression of miR-193a alleviated neuropathic pain in STZ-induced diabetic mice. Peripheral neuroinflammation in diabetic mice was suppressed by miR-193a overexpression. CONCLUSION: This research illustrates that miR-193a alleviates diabetic neuropathic pain in a mouse model through the inhibition of HMGB1 expression.

Anesthetics alleviate learning and memory impairment induced by electroconvulsive shock by regulation of NMDA receptor-mediated metaplasticity in depressive rats.

Along with its outstanding antidepressant effect, electroconvulsive shock (ECS) can induce learning and memory impairment. Propofol and ketamine have shown to be useful in alleviating the learning and memory impairment. Nevertheless, the mechanism still remains unclear. This study investigated the role of NMDA receptor (NMDAR)-mediated metaplasticity in the learning and memory impairment induced by ECS, as well as the neuroprotective effect of propofol and ketamine in depressive rats. Rats received ECS or ECS under anesthetics after chronic unpredictable mild stress procedure. Long-term potentiation (LTP) was tested by extracellular recording. LTD/LTP threshold was assessed by stimulation of different frequencies. Additionally, NMDAR-mediated field excitatory postsynaptic potential (fEPSP) and NMDAR input/output relationship were detected under hippocampal slice perfusion. Results showed that propofol or low-dose ketamine could partially alleviate ECS-induced LTP impairment, while propofol combined with low-dose ketamine almost reversed the LTP impairment. LTP under ECS was increased by stronger stimulation. ECS could up-regulated LTD/LTP threshold, while propofol or ketamine could down-regulate it. Moreover, ECS activated NMDAR, while propofol and ketamine could inhibit the activation of NMDAR. NMDAR input/output relationship decrease was induced by preconditioning (an analog of ECS in hippocampal slice), however, NMDAR input/output relationship increased by propofol or ketamine. In conclusion, ECS-induced cognitive impairment is caused by NMDAR-mediated metaplasticity via up-regulation of LTD/LTP threshold. Propofol or ketamine alleviates the cognitive impairment, possibly by down-regulating the threshold via inhibition of NMDAR activation induced by ECS.

Fibers with Hyper-Crosslinked Functional Porous Frameworks.

The incorporation of robust porous frameworks into polymer fibers with handleable morphologies and flexible chemical compositions exhibits significant advantages for device fabrication in a wide range of applications. However, the soft linear polymeric chains of the fibers make the generation of nanopores extremely challenging. Herein, a facile synthetic strategy based on a combination of functional monomer grafting and hyper-crosslinking technology is developed for the porous engineering of polymeric fibers. In this methodology, the nanoporous framework originating from the hyper-crosslinking of aromatic monomers is covalently grafted onto fibers, which is beneficial to retaining their unique fiber morphology and to preserving their excellent mechanical properties. Moreover, this promising protocol can be further extended to the porous functionalization of polymeric matrices with diverse morphologies for target-specific applications.

Piperidine Alkaloids with Diverse Skeletons from Anacyclus pyrethrum.

Fifteen new piperidine derivatives, pyracyclumines A-J (1-10), including five pairs of enantiomers, (+)-1/(-)-1 to (+)-5/(-)-5, together with three known compounds, agrocybenine (11), 4,6,6-trimethyl-5,6-dihydro-2(1 H)-pyridone (12), and 3,5,5-trimethyl-1,5-dihydro-2 H-pyrrol-2-one (13), were isolated from the roots of Anacyclus pyrethrum. Pyracyclumines A, B, and H (1, 2, and 8) possess a novel 6/5/6/6 dimeric piperidine skeleton, a unique 6/5/6 dimeric piperidine skeleton, and a 1,4,6-triazaindan skeleton, respectively. Pyracyclumine C (3) is based on a rare cyclopentane-piperidine framework. The structures of the isolated compounds were established by analysis of their NMR and HRESIMS data. The racemic pyracyclumines A-E (1-5) were further separated by chiral HPLC to give the enantiomers (+)-1/(-)-1 to (+)-5/(-)-5, for which the absolute configurations were determined by comparison of their experimental and calculated ECD spectra. The plausible biogenetic pathways of these piperidine alkaloids were proposed starting from the basic units of compounds 12 and 13. All of the isolated compounds were tested for their inhibitory effects on menin-mixed lineage leukemia 1 protein-protein interaction.

Effect of Low Dose of Ketamine on Learning Memory Function in Patients Undergoing Electroconvulsive Therapy-A Randomized, Double-Blind, Controlled Clinical Study.

OBJECTIVES: Converging evidence suggests that low doses of ketamine have antidepressant effects. The feasibility and safety of administering low doses of ketamine as adjunctive medication during electroconvulsive therapy (ECT) to enhance ECT efficacy and mitigate cognitive impairment has attracted much attention. This study investigated the effects of low doses of ketamine on learning and memory in patients undergoing ECT under propofol anesthesia. METHODS: This randomized, placebo-controlled, double-blind study recruited patients with moderate to severe depressive disorders who failed to respond to antidepressants and were scheduled to receive ECT. Participants were randomly assigned to a study group, which received an intravenous administration of 0.3 mg/kg ketamine and then underwent ECT under propofol anesthesia, and a control group, which received isovolumetric placebo (normal saline) and then underwent ECT under propofol anesthesia. The Hamilton Depression Rating Scale was used to assess the severity of depression after ECT. Before and after the ECT course, the Mini-mental State Examination and the Wechsler Memory Scale-Chinese-Revision were used to assess global cognitive and learning and memory functions, respectively. Psychotropic effects were assessed using the Brief Psychiatric Rating Scale. Vital signs and other adverse events were recorded for each ECT procedure. RESULTS: Of 132 patients recruited, 66 were assigned to each group; 63 patients in study groups and 64 patients in the control group completed the ECT course during the study. Afterward, the incidence of global cognitive impairment in the control group was higher than it was in the study group. In addition, the decline in the Wechsler Memory Scale-Chinese-Revision scale was greater in the control group than in the study group. The necessary ECT treatment times were shorter in the study group than in the control group (8 [7, 9] vs 9 [8, 10]). No significant escalations of the positive Brief Psychiatric Rating Scale scores or adverse events were observed in the study group when compared with the control group. CONCLUSIONS: As adjunctive medication, ketamine can attenuate learning and memory impairment, especially for short-term memory, caused by ECT performed under propofol anesthesia. Ketamine can also reduce ECT treatment times during the therapy course without inducing significant adverse effects.

Prevalence and risk factors for chronic pain following cesarean section: a prospective study.

BACKGROUND: Chronic post-surgical pain (CPSP) remains a major clinical problem which may be associated with impaired activities of daily life and decreased health-related quality of life. Although cesarean section is one of the most commonly performed operations, chronic pain after cesarean delivery has not been well-studied. The purpose of this prospective study was to assess the incidence and risk factors of chronic pain at 3, 6 and 12 months after cesarean delivery. METHODS: We prospectively investigated preoperative demographic and psychological factors, intraoperative clinical factors, and acute postoperative pain in a cohort of 527 women undergoing cesarean section. The women were interviewed and completed pain questionnaires after 3, 6 and 12 months. Questions were about pain intensity, frequency, and location, as well as medical treatment and impact on daily living. RESULTS: The incidence of CPSP at 3, 6 and 12 months after cesarean section was 18.3 %, 11.3 % and 6.8 %, respectively. Most of the women with CPSP experienced mild pain at rest. The incidence of moderate and severe pain on movement was high at 3 month, and then has a significant decrease at 6 and 12 months. CPSP had a negative influence on the activities of daily living. Independent predictors of CPSP at 3 months included higher average pain intensity on movement within 24 h postoperatively, preoperative depression, and longer duration of surgery. At 6 months, more severe pain during movement within 24 h of surgery and preoperative depression were predictive of pain persistence. And 12 months after surgery, only higher average pain score on movement within 24 h following cesarean section was found to be significant associated with CPSP. The three models all showed moderate discrimination and good calibration for the prediction of CPSP at 3, 6 and 12 months postoperatively. CONCLUSIONS: CPSP was not rare in women undergoing cesarean section. Patients with more intense of acute postoperative pain on movement, preoperative depression, and longer surgical time had greater risk for CPSP following surgery.

Guest-Induced Breathing Effect in a Flexible Molecular Crystal.

By introducing a flexible component into a molecular building block, we present an unprecedented alkyl-decorated flexible crystalline material with a breathing behavior. Its selective adsorption is derived from the breathing effect induced by a guest triggered alkyl transformation. This feature allows the crystal to take up 2.5 mmol g(-1) of chloroform with high adsorption selectivity (CHCl3 /EA >2000 for example), implying a potential application in sorption separation and chemical sensors.

Identification of metabolites of rupestonic acid in rat urine by liquid chromatography combined with electrospray ionization quadrupole time-of-flight tandem mass spectrometry.

Rupestonic acid, a potential anti-influenza agent, is an important and characteristic compound in Artemisia rupestris L., a well-known traditional Uighur medicine for the treatment of colds. In the present study, high-performance liquid chromatography combined with electrospray ionization quadrupole time-of-flight tandem mass spectrometry was used to detect and identify the metabolites in rat urine after oral administration of rupestonic acid. A total of 10 metabolites were identified or partially characterized. The structure elucidations of the metabolites were performed by comparing the changes in accurate molecular masses and fragment ions with those of the parent compound. The results showed that the main metabolites of rupestonic acid in rat urine were formed by oxidation, hydrogenation and glucuronidation. A metabolism pathway was proposed for the first time based on the characterized structures. This metabolism study can provide essential information for drug discovery, design and clinical application of rupestonic acid.

Polyelectrolyte multilayers on PTMSP as asymmetric membranes for gas separations: Langmuir-Blodgett versus self-assembly methods of anchoring.

Polyelectrolyte multilayers derived from poly(diallyldimethylamonium chloride) and poly(sodium 4-styrenesulfonate) have been deposited onto poly[1-(trimethylsilyl)-1-propyne] (PTMSP) with anchoring layers formed by Langmuir-Blodgett and self-assembly methods. Using gas permeation selectivity as a basis for judging the efficacy of each anchoring method, we have found that similar CO2/N2 selectivities (ranging from 110 to 140) could be achieved by both methods and that their permeances were also similar. Although LB anchors require fewer layers of polyelectrolyte to reach this level of selectivity, the greater ease associated with self-assembly and its applicability to curved, high-surface-area supports (e.g., PTMSP-coated hollow fibers) encourage its use with PTMSP in creating new membrane materials for the practical separation of gases.

Highly conjugated norditerpenoid and pyrroloquinoline alkaloids with potent PTP1B inhibitory activity from Nigella glandulifera.

Three norditerpenoid alkaloids, nigelladines A-C (1-3), and one pyrroloquinoline alkaloid, nigellaquinomine (4), all possessing new skeletons with highly conjugated systems, were isolated from Nigella glandulifera. The 8aS-configuration for 1 and 2 was determined by comparison of the experimental and calculated electronic circular dichroism spectra. These alkaloids exhibited potent protein tyrosine phosphatase 1B (PTP1B) inhibitory activity but are devoid of cytotoxicity against the A431 cell line at 100 µM.