Incidence and clinical features of HHV-7 detection in lower respiratory tract in patients with severe pneumonia: a multicenter, retrospective study.

PURPOSE: The significance of detecting human herpesvirus 7 (HHV-7) in the lower respiratory tract of patients with severe pneumonia is unclear. This study aims to evaluate the clinical characteristics and prognosis of detecting HHV-7 in the lower respiratory tract of patients with severe pneumonia. METHODS: Patients with severe pneumonia requiring invasive mechanical ventilation and underwent commercial metagenomic next-generation sequencing (mNGS) testing of bronchoalveolar lavage fluid from January 2019 to March 2023 were enrolled in 12 medical centers. Clinical data of patients were collected retrospectively, and propensity score matching was used for subgroup analysis and mortality assessment. RESULTS: In a total number of 721 patients, 45 cases (6.24%) were identified with HHV-7 positive in lower respiratory tract. HHV-7 positive patients were younger (59.2 vs 64.4, p = 0.032) and had a higher rate of co-detection with Cytomegalovirus (42.2% vs 20.7%, p = 0.001) and Epstein-Barr virus (35.6% vs 18.2%, p = 0.008). After propensity score matching for gender, age, SOFA score at ICU admission, and days from ICU admission to mNGS assay, there was no statistically significant difference in the 28-day mortality rate between HHV-7 positive and negative patients (46.2% vs 36.0%, p = 0.395). Multivariate Cox regression analysis adjusting for gender, age, and SOFA score showed that HHV-7 positive was not an independent risk factor for 28-day mortality (HR 1.783, 95%CI 0.936-3.400, p = 0.079). CONCLUSION: HHV-7 was detected in the lungs of 6.24% of patients with severe pneumonia. The presence of HHV-7 in patients with severe pneumonia requiring invasive mechanical ventilation is associated with a younger age and co-detected of Cytomegalovirus and Epstein-Barr virus. While HHV-7 positivity was not found to be an independent risk factor for mortality in this cohort, this result may have been influenced by the relatively small sample size of the study.

Dual resource utilization for tannery sludge: Effects of sludge biochars (BCs) on volatile fatty acids (VFAs) production from sludge anaerobic digestion.

Resource utilization of organic matters in tannery sludge has drawn great attention. In this paper, the influences of sludge biochars (BCs) on volatile fatty acids (VFAs) production from the anaerobic digestion of sludge supernatant (SST) were investigated. Experimental results demonstrated that the VFAs yields improved in the presence of BCs with rich functional groups. The maximum yield of VFAs was 1037.5 mg/g SCOD with the addition of BC-1 biochar (zeta potential -50.42 mV). BCs decreased ammonia nitrogen concentration, thus reducing inhibition for bacteria during the anaerobic digestion. Microbial community analysis indicated that the BCs affected microbial community structures and contributed to a favorable environment for bacteria. Especially, the BC-1 biochar with rich functional groups enhanced the relative abundance of acid-forming bacteria (Clostridiales). A dual strategy was proposed to improve the resource utilization efficiency for tannery sludge.

Roles of hydrothermal-alkaline treatment in tannery sludge reduction: rheological properties and sludge reduction mechanism analysis.

The hydrothermal-alkaline treatment (HAT) is an efficient sludge reduction method. However, the roles of HAT in tannery sludge reduction are not very clear. In this study, the sludge reduction mechanism of HAT was explored. The results showed that HAT had good performance for the organic dissolution of tannery sludge. The reduction of the sludge mass was calculated by the mass of the separated wet sludge solid (4000 rpm, 10 min) before and after HAT. The HAT parameters for sludge reduction (SR) were optimized by the Box-Behnken, and the sludge reduction was 62.5% under optimal conditions (198 °C, 87 min and 8.7 g L-1 NaOH). The soluble organics, especially a polysaccharide (PS) and ammonia nitrogen (NH3-N), showed a close correspondence with the SR ratio. The rheological properties of the sludge indicated that the reticular structures in the sludge were destroyed after HAT. The tannery sludge solid became more pyknotic than raw sludge after the hydrothermal-alkaline treatment. The tannery sludge reduction can be attributed to the damage of reticular structures, organic dissolution and release of bound water.