Esterification catalyzed by an efficient solid acid synthesized from PTSA and UiO-66(Zr) for biodiesel production.

p-Toluenesulfonic acid (PTSA) is a typical homogeneous acid for biodiesel production. Due to the shortcomings of high deliquescence and non-recyclability, it is necessary to synthesize a recyclable solid acid. For the sake of this, UiO-66(Zr) is used to support PTSA through defect coordination, and four different preparation routes are compared. The obtained catalyst (UiO-G) is characterized with thermogravimetry analysis (TG), X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), pyridine FTIR spectroscopy (py-FTIR), nitrogen adsorption-desorption, and base titration. In addition, the effects of esterification parameters on conversion are investigated to obtain the optimal conditions. To further verify the high catalytic activity of UiO-G, the kinetic model of solid-liquid-liquid esterification is established, in which the kinetic parameters of activation energy, reaction order, and exponential factor are calculated. Results indicate the PTSA is successfully inserted in UiO-66(Zr) without destroying its original structure. With that, the maximum conversion of oleic acid to biodiesel of 91.3% is achieved with a molar ratio of methanol/oleic acid of 12 and a catalyst amount of 8 wt% at 70 °C for 2 h. Moreover, UiO-G could remarkably reduce the activation energy, where the activation energy is 28.61 kJ mol-1, the average reaction order is 1.51, and the pre-exponential factor is 29.11 min-1.

Corrigendum: Diagnostic efficiency of metagenomic next-generation sequencing for suspected spinal tuberculosis in China: a multicenter prospective study.

[This corrects the article DOI: 10.3389/fmicb.2022.1018938.].

Diagnostic efficiency of metagenomic next-generation sequencing for suspected spinal tuberculosis in China: A multicenter prospective study.

Background: The pathogens of suspected spinal tuberculosis (TB) include TB and non-TB bacteria. A rapid and effective diagnostic method that can detect TB and non-TB pathogens simultaneously remains lacking. Here, we used metagenomic next-generation sequencing (mNGS) to detect the pathogens in patients with suspected spinal TB. Methods: The enrolled patients with suspected spinal TB were regrouped three times into patients with spinal infection and controls, patients with spinal TB and controls, and patients with non-TB spinal infection and controls. We tested the three groups separately by using mNGS and conventional detection methods. Results: Ultimately, 100 patients were included in this study. Pathogens were detected in 82 patients. Among the 82 patients, 37 had TB and 45 were infected with other bacteria. In patients with spinal infection, the sensitivity of the mNGS assay was higher than that of culture and pathological examination (p < 0.001, p < 0.001). The specificity of the mNGS assay was not statistically different from that of culture and pathological examination (p = 1.000, p = 1.000). In patients with spinal TB, no statistical difference was found between the sensitivity of the mNGS assay and that of Xpert and T-SPOT.TB (p = 1.000, p = 0.430). The sensitivity of the mNGS assay was higher than that of MGIT 960 culture and pathological examination (p < 0.001, p = 0.006). The specificities of the mNGS assay, Xpert, MGIT 960 culture, and pathological examination were all 100%. The specificity of T-SPOT.TB (78.3%) was lower than that of the mNGS assay (100%; p < 0.001). In patients with non-TB spinal infection, the sensitivity of the mNGS assay was higher than that of bacterial culture and pathological examination (p < 0.001, p < 0.001). The specificity of the mNGS assay was not statistically different from that of bacterial culture and pathological examination (p = 1.000, p = 1.000). Conclusion: Data presented here demonstrated that mNGS can detect TB and non-TB bacteria simultaneously, with high sensitivity, specificity and short detection time. Compared with conventional detection methods, mNGS is a more rapid and effective diagnostic tool for suspected spinal TB.

Metagenomic Next-Generation Sequencing Improves Diagnosis of Osteoarticular Infections From Abscess Specimens: A Multicenter Retrospective Study.

Background: We conducted this retrospective study to reveal the accuracy of metagenomic next-generation sequencing (mNGS) for diagnosing osteoarticular infections from fresh abscess specimens obtained from patients in an HIV-naive population. Methods: We retrospectively analyzed hospital records at three participating TB-specialized hospitals for patients admitted with suggestive diagnoses of osteoarticular tuberculosis between January 2018 and August 2019. Abscess specimens obtained from each patient were tested via pathogen culture, GeneXpert Mycobacterium tuberculosis (MTB)/rifampicin (RIF), and mNGS assay. Results: A total of 82 abscess samples were collected from patients with osteoarticular infections, including 53 cases with (64.6%) bacterial, 21 (25.6%) with mycobacterial, 7 (8.5%) with fungal, and 1 (1.2%) with actinomycetal organisms detected. Analysis of mNGS assay results identified potential pathogens in all cases, with M. tuberculosis complex (MTBC) most frequently isolated, followed by Staphylococcus aureus and Brucella melitensis. Conventional culture testing identified causative pathogens in only 48.4% of samples, a significantly lower rate than the mNGS pathogen identification rate (100%, p < 0.01). Culture-positive group specimens yielded significantly greater numbers of sequence reads than did culture-negative group specimens (p < 0.01). Of patients receiving surgical interventions and mNGS-guided treatment, 76 (92.7%) experienced favorable outcomes by the time of follow-up assessment at 3 months post-treatment. Notably, MTBC detection in two patients experiencing treatment failure suggests that they had mixed infections with MTBC and other pathogens. Conclusion: Results presented here demonstrate that mNGS has a greater pathogen detection rate in osteoarticular infections than conventional culture-based methods.

Efficacy, safety and prognosis of treating neurological deficits caused by spinal tuberculosis within 4 weeks' standard anti-tuberculosis treatment: A single medical center's experience.

The present study aimed to retrospectively analyze the safety and efficacy of the early surgical management of thoracic tuberculosis (TB) in patients with neurological deficits. The medical data of patients with thoracic TB exhibiting neurological deficit in the Chest Hospital of Hebei Province were retrospectively reviewed. A total of 234 cases, including 123 males and 115 females, were recruited in the present study. Their pre- and postoperative neurological deficit and pain levels were assessed using the 2002 American spinal injury association (ASIA) impairment scale and visual analog scale, respectively. Patients were divided into two groups according to whether their preoperative standardized anti-TB treatment time was ≥4 weeks or <4 weeks. There was no difference in blood loss and operation time between the two groups. The erythrocyte sedimentation rate was higher in patients receiving standard anti-TB <4 weeks prior to and 1 month following surgery compared with the ≥4 weeks group, but the difference was not significant 6 months following surgery. ASIA scale scores all increased significantly 1 month following surgery in the <4 weeks group compared with the ≥4 weeks group (P=0.001) though there was no difference between the scores prior to surgery. ASIA scale scores improved to 4.4±0.5 and 4.5±0.4 in patients with anti-TB treatment times of ≥4 weeks and <4 weeks, respectively, 24 months following surgery (P=0.0895). The present study demonstrated that for patients with thoracic TB exhibiting neurological deficit, early surgical management following <4 weeks' standard anti-TB treatment is recommended. It may relieve spinal cord compression and also benefit the early recovery of neurological function in these patients.

[TREATING SACROILIAC JOINT TUBERCULOSIS WITH RIFAMPICIN-LOADED OsteoSet].

OBJECTIVE: To assess the safety, feasibility, and effectiveness of medical calcium sulfate (OsteoSet) mixed with powder for injection of rifampicin after radical debridement in the treatment of sacroiliac joint tuberculosis. METHODS: A retrospective analysis was made on the clinical data from 27 patients with sacroiliac joint tuberculosis who underwent debridement surgery and local bone graft of OsteoSet artificial bone impregnated with powder for injection of rifampicin between August 2006 and August 2010. There were 10 males and 17 females with an average age of 35.2 years (range, 16-64 years). The mean disease duration was 7.5 months (range, 1.5-16 months). The left sacroiliac joint was involved in 16 cases, the right side in 10 cases, and both sides in 1 case; Of them, 18 cases had iliac fossa abscess and 6 cases of buttocks abscess. According to the classification system by Kim, there were 9 cases of type III and 18 cases of type IV. The preoperative Majeed score was 61.23?6.49, including good in 4 patients, general in 19 patients, and poor in 4 patients. RESULTS: All patients achieved wound healing by first intention; no complications of pelvic infection, peripheral nerve injury, and lower extremity deep vein thrombosis occurred. Twenty-six patients were followed up 16 months on average (range, 12-24 months). All the patients had normal sense and movement of both lower limbs; no perineum sensory disturbance was found. One case of multi-drug resistant had local recurrence at 3 months after operation, which was cured after adjusting anti-tuberculosis drugs, nutritional support, enhancing immunity with thymopentin, and second operation. Bone union was observed at 10.5 months on average (range, 9-12 months) in 25 patients, and clinical symptoms disappeared with no recurrence or complication, and they returned to previous work. The Majeed score at last follow-up was 92.31 +/- 3.36, showing significant difference when compared with preoperative score (t = -32.76, P=0.00). The results were excellent in 22 patients, good in 4 patients, and the excellent and good rate was 100%, showing signi.ficant difference compared with the preoperative one (chi2=31.93, P=0.00). CONCLUSION: Bone graft interbody fusion surgery with rifampicin loaded OsteoSet is one of the effective methods to treat sacroiliac joint tuberculosis.

All-trans retinoic acid and arsenic trioxide induce apoptosis and modulate intracellular concentrations of calcium in hepatocellular carcinoma cells.

We investigated the effects of all-trans retinoic acid (ATRA) and arsenic trioxide (ATO), alone and in combination, on apoptosis and intracellular calcium concentration in hepatocellular carcinoma (HepG2) cells. We used HepG2 cells to test the effects of ATRA and ATO, individually and in combination, on cell proliferation, apoptosis, and intracellular-free calcium concentration. The results indicate that each drug decreased cell proliferation, increased apoptosis, and increased intracellular-free calcium in a time- and dose-dependent manner. We also calculated the coefficients of drug interaction for sub-threshold administration of both drugs in combination (1 µmol/L each). ATRA and ATO acted synergistically in inhibition of cell proliferation and additively in the promotion of apoptosis. All-trans retinoic acid and ATO interacted synergistically to reduce cell proliferation in HepG2 cells.