Double Bond Geometric Isomers of Pentaketide Ansamycins from Streptomyces sp. S008.

Six new pentaketide ansamycins, namely, shengliangmycins A-F (1-6, respectively), were obtained from the fermentation products of Streptomyces sp. S008OEslmR2 that was derived by constitutive expression of LAL regulator gene slmR2. The structures of 1-6 were determined through comprehensive spectroscopic analysis and single-crystal X-ray diffraction. Compound 1 has a cis-C6═C7 bond, which is different from that of compounds 2-5. Compounds 3-6 feature a morpholinone structural moiety, whereas 5 is characterized by a pyrazoline ring, which is rare in natural products.

Surgical treatment of rare pediatric cardiac myxomas:12 years clinical experience in a single institution.

BACKGROUND: Primary cardiac tumors are rare, and cardiac myxoma (CM) accounts for the majority of these tumors. Most of the reports in the literature are case reports. This study summarizes our clinical experience in the surgical treatment of CM over the past 12 years. METHODS: We retrospectively analyzed the clinical data of 23 children with CM(8 boys, 15 girls; median age: 8.92 months, range: 2 years 5 months-12 years 9 months; body weight: 11-45 kg, median body weight: 28.21 kg) admitted to our hospital in the previous 12 years, and we statistically analyzed their clinical manifestations and surgical methods. RESULTS: 23 cases underwent myxoma excision under cardiopulmonary bypass(CPB). The follow-up period was 0.2 to 12.6 years (mean:7.2 years). Two patients could not be traced, and the follow-up completion rate was 91.30%. One patient (4.35%) died of myocardial infarction early after surgery with low continuous cardiac output. There were no cerebral embolism, acute heart failure, atrioventricular block and other related complications in 19 cases. A patient with cerebral infarction complicated with right hemiplegia recovered well after rehabilitation treatment. There was no recurrence of CM in 19 cases and all patients recovered after surgery. One patient relapsed 5 years after surgery, and no tumor recurrence was observed after the second surgery. Among the 20 long-term survivors, 13 (65.00%) were NYHA Class I patients and 7(35.00%) were NYHA Class II patients. CONCLUSIONS: Although CM in children is rare, it may cause cerebral infarction and other multi-organ embolism. Once CM is found and removed as soon as possible, it can reduce serious complications. If the complete resection is possible, surgery provides better palliation. Follow-up echocardiographic should be paid attention to after surgery.

A simple and feasible fluorescent approach for rapid detection of hexavalent chromium based on gold nanoclusters.

Hexavalent chromium (Cr6+) owns hypertoxicity, non-biodegradability, and carcinogenicity, thus the detection of Cr6+ is of paramount significance for environmental monitoring and human health maintenance. Herein, a simple, rapid, and feasible fluorescent method based on gold nanoclusters (AuNCs) was established for determination of Cr6+. The AuNCs was coated by a simple and fast one-pot method using d-histidine (d-His) and polylysine (P-Lys) as stabilizers and reductants, which could be quenched by the addition of Cr6+ owing to the aggregation of AuNCs and fluorescence resonance energy transfer (FRET) between AuNCs and Cr6+. Under the optimal conditions, the fluorescent sensor exhibited good linearity within 10-10000 µg/L with limit of detection of 7.2 µg/L. The developed sensor possessed favorable sensitivity and selectivity. Additionally, the proposed method also had favorable recovery with good precision and accuracy within the actual sample, including celery cabbage, rice, capsule shell, and river water.

Surgical treatment of congenital diaphragmatic hernia in a single institution.

BACKGROUND: This study aimed to evaluate the effectiveness of video-assisted thoracic surgery for the treatment of congenital diaphragmatic hernia (CDH) in a larger series compared with conventional open surgery. Additionally, we summarized the experience of thoracoscopic surgery in the treatment of CDH in infants. METHODS: We retrospectively analysed the clinical data of 109 children with CDH who underwent surgical treatment at the Department of Cardiothoracic Surgery of Children's Hospital of Chongqing Medical University from January 2011 to January 2021. According to the surgical method, the children were divided into an open group (62 cases) and a thoracoscopy group (47 cases).Patients who underwent surgical correction had the diaphragmatic defect size graded (A-D) using a standardized system. We compared the operation time, intraoperative blood loss, postoperative mechanical ventilation time, postoperative hospital stay, postoperative CCU admission time and other surgical indicators as well as the recurrence rate, mortality rate and complication rate of the two groups of children. RESULTS: The index data on the operation time, intraoperative blood loss, postoperative mechanical ventilation time, postoperative hospital stay and postoperative CCU admission time were better in the thoracoscopy group than in the open group. The difference between the two groups was statistically significant (P < 0.05). We compared the number of incision infections, lung infections, atelectasis, pleural effusion, and chylothorax between the two groups. There were more children in the open group than in the thoracoscopy group. The overall incidence of postoperative complications in the open group (51.61%) was higher than that in the thoracoscopy group (44.68%).The recurrence rate of the thoracoscopy group (8.51%) was higher than that of the open group (3.23%). In the open group, 7 patients died of respiratory distress after surgery, and no patients died in the thoracoscopy group. CONCLUSIONS: Thoracoscopic surgery and open surgery can effectively treat CDH. Compared with conventional open surgery, thoracoscopy has the advantages of shorter operation time, less trauma, faster recovery and fewer complications. We believe that thoracoscopic surgery for type A/B diaphragmatic defect has certain advantages, but there is a risk of recurrence.

Carbon dots combined with masking agent for high selectivity detection of Cr(VI) to overcome interference associated challenges.

Hexavalent chromium (Cr(VI)) determination is of great importance to the public health because of its extensive sources and high toxicity. However, interference from non-target ions and complex matrix remains challenges for Cr(VI) detection. In this work, we constructed a novel sensing system for high selectivity detection of Cr(VI), which is composed of strong emitting carbon dots (CE-CDs) and a specific masking agent. The detection conditions, anti-interference capability and the sensing and masking mechanisms of CE-CDs-based sensing method were systematically investigated. The results revealed that the optimal detection conditions included pH 4-10, reaction time 180 s and CE-CDs concentration 18 mg/L. Under optimal conditions, the linear range of the method was up to 500 µm, and the detection limit was as low as 23 nM. In addition, the interference of Hg(II) can be accurately eliminated by using DMPS, an effective masking agent. During the sensing process, inner filter effect and ion-molecular interaction between Cr(VI) and CE-CDs accounted for the fluorescence quenching mechanism, while the efficient masking was attributed to the strong coordination interaction between Hg(II) and DMPS. Most notably, this method had broad applicability, even for the trace detection of Cr(VI) in colored leather with complex matrix. These findings indicate that this approach is expected to open up new avenues for Cr(VI) detection.

Langerhans cell histiocytosis of the rib in an adult: A case report and review of the literature.

INTRODUCTION AND IMPORTANCE: Langerhans cell histiocytosis (LCH) is a rare neoplastic hyperplasia with an unknown etiology. It is clinically rare for patients with solitary rib lesion and pathological fracture. In this article, we report a case of LCH in solitary involvement of rib and provide a review of the available literature. CASE PRESENTATION: A 24-year-old female patient complained of right chest and back pain for 10 days. CT showed a fracture in the right 6th rib. Findings on X-ray, and CT were suggestive of homogeneous osteolytic lesion of the right 6th rib. The rib tumor was then resected and the surrounding muscles and soft tissues were accordingly resected. CLINICAL DISCUSSION: The patient was diagnosed with pathological rib fracture, and the patient was pathologically diagnosed with LCH. After surgery, no local recurrence or distant metastasis was reported during the one-year follow-up. CONCLUSIONS: Most of the solitary tumorous lesions in rib in adults call for various differential diagnoses. Although single-site, single-system LCH of the rib is one of the rarest causes of bone tumor in adults, it can be treated successfully with surgical intervention. LCH should be considered in the diagnosis of an adult patient with a rib mass.

Colorimetric and fluorescent probes for the rapid detection of profenofos in farmland system.

Colorimetric and fluorescent sensors were developed for the detection of profenofos. The colorimetric assay relied on the aggregation of cysteine modified gold nanoparticles (Au-cys) composite caused by the hydrogen bond and Au-S bond between profenofos and Au-cys. The further addition of S, N-doped carbon quantum dots (CDs) (fluorescence quantum yield up to 98%) into the Au-cys system depended on the change of fluorescence intensity of Au-cys-CDs owing to the inner filter effect between Au-cys and CDs. Under the optimal conditions, the sensor exhibits good linearity within 0.2-1.2 mg L-1 and 20-320 µg L-1, and limit of detection of 21.7 µg L-1 and 5.5 µg L-1 in colorimetry and fluorescence mode, respectively. The developed sensor did not only possess favorable selectivity and sensitivity, but also feasibility of usage in the actual detection of profenofos in farmland system samples.

A new simplified technique in thoracoscopic repair of congenital diaphragmatic hernia.

BACKGROUND: This study aims to describe a new method of repairing the diaphragm with a venipuncture indwelling needle under thoracoscopy to treat congenital diaphragmatic hernia (CDH). METHODS: We retrospectively analysed the clinical data of 43 children with CDH who underwent CDH repair with new technology in our hospital. In this study, we used the venipuncture indwelling needle suture method to treat children with CDH. RESULTS: In this study, 3 children were converted to open surgery, and the remaining 40 children achieved better clinical results. Follow-up of 43 children was performed for 1 month to 6 years. Except for two patients who relapsed after surgery, there was no recurrence after another operation. The remaining 41 children recovered well; there were no deaths or serious complications. Postoperative chest X-ray and gastrointestinal angiography showed that the abdominal organs were in a normal position. CONCLUSIONS: The use of a venipuncture indwelling needle to suture the diaphragm under thoracoscopy is a simple new technique. This method can not only improve the efficiency of sutures but also better handle the opening of the "V"-shaped defect of the diaphragm. At the same time, it has the advantages of minimal trauma, fast recovery, and improved cosmetic appearance.

Rapid and selective detection of aluminum ion using 1,2,3-triazole-4,5-dicarboxylic acid-functionalized gold nanoparticle-based colorimetric sensor.

A highly selective, sensitive, rapid, low-cost, simple and visual colorimetric system for Al3+ ion detection was developed based on gold nanoparticles (AuNPs) modified with 1,2,3-triazole-4,5-dicarboxylic acid (TADA). The modified gold nanoparticles (TADA-AuNPs) were first prepared by sodium citrate (Na3Ct) reduction of chloroauric acid (HAuCl4) and then capped with a TADA ligand. Five TADA-AuNPs sensors were constructed with sodium citrate (Na3Ct)/chloroauric acid (HAuCl4) under different molar ratios. Results showed that the molar ratio of Na3Ct/HAuCl4, TADA-AuNPs concentration, pH range and detection time had obvious influences on the performance of this colorimetric method. The optimal detection conditions for Al3+ ions were as follows: Na3Ct/HAuCl4 molar ratio of 6.4 : 1, 0.1 mM of TADA-AuNPs concentration, 4-10 pH range and 90 s of detection time. Under the optimal conditions and using diphenyl carbazone (DPC) as a Cr3+ masking agent, this colorimetric sensor exhibited outstanding time efficiency, selectivity and sensitivity for Al3+ detection. In particular, the detection limits of this sensor obtained via UV-vis and the naked eye were 15 nM and 1.5 µM, respectively, which were much lower than the current limit (3.7 µM) for drinking water in WHO regulation and better than the previous reports. Moreover, this colorimetric sensing system could be used to for on-site, trace level and real-time rapid detection of Al3+ in real water samples.

Surgical treatment of 125 cases of congenital diaphragmatic eventration in a single institution.

BACKGROUND: This study sought to investigate the clinical characteristics of congenital diaphragmatic eventration (CDE) and to compare the efficacies of thoracoscopy and traditional open surgery in infants with CDE. METHODS: We retrospectively analyzed the clinical data of 125 children with CDE (90 boys, 35 girls; median age: 12.2 months, range: 1 h-7 years; body weight: 1.99-28.5 kg, median body weight: 7.87 ± 4.40 kg) admitted to our hospital in the previous 10 years, and we statistically analyzed their clinical manifestations and surgical methods. RESULTS: A total of 108 children in this group underwent surgery, of whom 67 underwent open surgery and 41 underwent thoracoscopic diaphragmatic plication. A total of 107 patients recovered well postoperatively, except for 1 patient who died due to respiratory distress after surgery. After 1-9.5 years of follow-up, 107 patients had significantly improved preoperative symptoms. During follow-up, the location of the diaphragm was normal, and no paradoxical movement was observed. Eleven of the 17 children who did not undergo surgical treatment did not have a decrease in diaphragm position after 1-6 years of follow-up. The index data on the operation time, intraoperative blood loss, chest drainage time, postoperative mechanical ventilation time, postoperative hospital stay and postoperative CCU admission time were better in the thoracoscopy group than in the open group. The difference between the two groups was statistically significant (P < 0.05). CONCLUSIONS: The clinical symptoms of congenital diaphragmatic eventration vary in severity. Patients with severe symptoms should undergo surgery. Both thoracoscopic diaphragmatic plication and traditional open surgery can effectively treat congenital diaphragmatic eventration, but compared with open surgery, thoracoscopic diaphragmatic plication has the advantages of a short operation time, less trauma, and a rapid recovery. Thus, thoracoscopic diaphragmatic plication should be the first choice for children with congenital diaphragmatic eventration.

8-Deoxy-Rifamycin Derivatives from Amycolatopsis mediterranei S699 ΔrifT Strain.

Proansamycin X, a hypothetical earliest macrocyclic precursor in the biosynthesis of rifamycin, had never been isolated and identified. According to bioinformatics analysis, it was proposed that RifT (a putative NADH-dependent dehydrogenase) may be a candidate target responsible for the dehydrogenation of proansamycin X. In this study, the mutant strain Amycolatopsis mediterranei S699 ΔrifT was constructed by deleting the rifT gene. From this strain, eleven 8-deoxy-rifamycin derivatives (1-11) and seven known analogues (12-18) were isolated. Their structures were elucidated by extensive analysis of 1D and 2D NMR spectroscopic data and high-resolution ESI mass spectra. Compound 1 is a novel amide N-glycoside of seco-rifamycin. Compounds 2 and 3 feature conserved 11,12-seco-rifamycin W skeleton. The diverse post-modifications in the polyketide chain led to the production of 4-11. Compounds 2, 3, 5, 6, 13 and 15 exhibited antibacterial activity against Staphylococcus aureus (MIC (minimal inhibitory concentration) values of 10, 20, 20, 20, 40 and 20 µg/mL, respectively). Compounds 14, 15, 16, 17 and 18 showed potent antiproliferative activity against KG1 cells with IC50 (half maximal inhibitory concentration) values of 14.91, 44.78, 2.16, 18.67 and 8.07 µM, respectively.

DNA interaction studies of tridentate bridged Ru(II)-Pt(II) mixed-metal supramolecules.

Reported herein are studies of the concentration and temperature dependent interactions with DNA of the stereochemically defined mixed-metal supramolecular complexes, [(tpy)Ru(tppz)PtCl](PF(6))(3) and [ClPt(tppz)Ru(tppz)PtCl](PF(6))(4) (tpy=2,2':6',2''-terpyridine and tppz=2,3,5,6-tetrakis(2-pyridyl)pyrazine). These metal complexes couple a ruthenium based light absorber (LA) to the bioactive platinum sites (BAS) using a tridentate bridging ligand (BL). The complexes exhibit intense Ru-->tppz(pi*) metal to ligand charge transfer (MLCT) transitions in the visible region and adopt a square planar geometry around the Pt(II) center. The effect of incubating these metal complexes with DNA on the subsequent migration of DNA through an agarose gel was found to be more dramatic than that observed for the well known anticancer drug, cis-[Pt(NH(3))(2)Cl(2)] (cisplatin). This effect was enhanced with increased incubation temperature. Unwinding of supercoiled plasmid DNA was found to be more pronounced for the trimetallic complex, [ClPt(tppz)Ru(tppz)PtCl](PF(6))(4), than for the bimetallic complex, [(tpy)Ru(tppz)PtCl](PF(6))(3).

Synthesis and study of the spectroscopic and redox properties of Ru(II),Pt(II) mixed-metal complexes bridged by 2,3,5,6-tetrakis(2-pyridyl)pyrazine.

The mixed-metal supramolecular complexes [(tpy)Ru(tppz)PtCl](PF6)3 and [ClPt(tppz)Ru(tppz)PtCl](PF6)4 (tpy = 2,2':6',2''-terpyridine and tppz = 2,3,5,6-tetrakis(2-pyridyl)pyrazine) were synthesized and characterized. These complexes contain ruthenium bridged by tppz to platinum centers to form stereochemically defined linear assemblies. X-ray crystallographic determinations of the two complexes confirm the identity of the metal complexes and reveal intermolecular interactions of the Pt sites in the solid state for [(tpy)Ru(tppz)PtCl](PF6)3 with a Pt...Pt distance of 3.3218(5) A. The (1)H NMR spectra show the expected splitting patterns characteristic of stereochemically defined mixed-metal systems and are assigned with the use of (1)H-(1)H COSY and NOESY. Electronic absorption spectroscopy displays intense ligand-based pi --> pi* transitions in the UV and MLCT transitions in the visible. Electrochemically [(tpy)Ru(tppz)PtCl](PF6)3 and [ClPt(tppz)Ru(tppz)PtCl](PF6)4 display reversible Ru (II/III) couples at 1.63 and 1.83 V versus Ag/AgCl, respectively. The complexes display very low potential tppz (0/-) and tppz(-/2-) couples, relative to their monometallic synthons, [(tpy)Ru(tppz)](PF6)2 and [Ru(tppz)2](PF6)2, consistent with the bridging coordination of the tppz ligand. The Ru(dpi) --> tppz(pi*) MLCT transitions are also red-shifted relative to the monometallic synthons occurring in the visible centered at 530 and 538 nm in CH3CN for [(tpy)Ru(tppz)PtCl](PF6)3 and [ClPt(tppz)Ru(tppz)PtCl](PF6)4, respectively. The complex [(tpy)Ru(tppz)PtCl](PF6)3 displays a barely detectable emission from the Ru(dpi) --> tppz(pi*) (3)MLCT in CH 3CN solution at RT. In contrast, [ClPt(tppz)Ru(tppz)PtCl](PF6)4 displays an intense emission from the Ru(dpi) --> tppz(pi*) (3)MLCT state at RT with lambda max(em) = 754 nm and tau = 80 ns.