Efficient production of single cell protein from biogas slurry using screened alkali-salt-tolerant Debaryomyces hansenii.

Production of single cell protein (SCP) by recovering ammonia nitrogen from biogas slurry shows great potential against protein scarcity and unsustainable production of plant and animal proteins. Herein, a high-alkali-salt-tolerant yeast strain, Debaryomyces hansenii JL8-0, was isolated and demonstrated for high-efficient SCP production. This strain grew optimally at pH 8.50 and 2500 mg/L NH4+-N, and it could efficiently utilize acetate as the additional carbon source. Under optimal conditions, SCP biomass of 32.21 g/L and productivity of 0.32 g/L·h-1 were obtained in fed-batch fermentation. Remarkably, nearly complete (97.40 %) ammonia nitrogen from biogas slurry was recovered, probably due to its high affinity for NH4+-N. Altogether, this strain showed advantages in terms of cell biomass titer, productivity, and yield. A cultivation strategy was proposed by co-culturing D. hansenii with other compatible yeast strains to achieve high-efficient SCP production from biogas slurry, which could be a promising alternative technology for biogas slurry treatment.

Inversely engineered biomimetic flexible network scaffolds for soft tissue regeneration.

Graft-host mechanical mismatch has been a longstanding issue in clinical applications of synthetic scaffolds for soft tissue regeneration. Although numerous efforts have been devoted to resolve this grand challenge, the regenerative performance of existing synthetic scaffolds remains limited by slow tissue growth (comparing to autograft) and mechanical failures. We demonstrate a class of rationally designed flexible network scaffolds that can precisely replicate nonlinear mechanical responses of soft tissues and enhance tissue regeneration via reduced graft-host mechanical mismatch. Such flexible network scaffold includes a tubular network frame containing inversely engineered curved microstructures to produce desired mechanical properties, with an electrospun ultrathin film wrapped around the network to offer a proper microenvironment for cell growth. Using rat models with sciatic nerve defects or Achilles tendon injuries, our network scaffolds show regenerative performances evidently superior to that of clinically approved electrospun conduit scaffolds and achieve similar outcomes to autologous nerve transplantation in prevention of target organ atrophy and recovery of static sciatic index.

Endemic medicinal plant distribution correlated with stable climate, precipitation, and cultural diversity.

Medicinal plants provide crucial ecosystem services, especially in developing countries such as China, which harbors diverse endemic medicinal plant species with substantial cultural and economic value. Accordingly, understanding the patterns and drivers of medicinal plant distribution is critical. However, few studies have investigated the patterns and drivers of endemic medicinal plants distribution in China. Here, we linked endemic medicinal plants distribution with possible explanatory variables, i.e., paleoclimate change, contemporary climate, altitudinal range and ethnic minority human population size at the prefecture city level in China. Our results show that endemic medicinal plants are concentrated in southern China, especially in southwestern China. Notably, both endemic medicinal plant species richness and the ratio of endemic medicinal plant species richness are negatively associated with glacial-interglacial anomaly in temperature, and positively associated with contemporary precipitation and altitudinal range. In addition, we found that endemic medicinal plant species richness is positively associated with ethnic minority population sizes as well as its ratio to the overall population size. These findings suggest that the distribution of endemic medicinal plants is determined by multiple drivers. Furthermore, our findings stress that dramatic future climate changes and massive anthropogenic activities in southern China pose great challenges to the conservation of China's endemic medicinal plants.

Leaf Venation Architecture in Relation to Leaf Size Across Leaf Habits and Vein Types in Subtropical Woody Plants.

Leaves are enormously diverse in their size and venation architecture, both of which are core determinants of plant adaptation to environments. Leaf size is an important determinant of leaf function and ecological strategy, while leaf venation, the main structure for support and transport, determines the growth, development, and performance of a leaf. The scaling relationship between venation architecture and leaf size has been explored, but the relationship within a community and its potential variations among species with different vein types and leaf habits have not been investigated. Here, we measured vein traits and leaf size across 39 broad-leaved woody species within a subtropical forest community in China and analyzed the scaling relationship using ordinary least squares and standard major axis method. Then, we compared our results with the global dataset. The major vein density, and the ratio of major (1° and 2°) to minor (3° and higher) vein density both geometrically declined with leaf size across different vein types and leaf habits. Further, palmate-veined species have higher major vein density and a higher ratio of major to minor vein density at the given leaf size than pinnate-veined species, while evergreen and deciduous species showed no difference. These robust trends were confirmed by reanalyzing the global dataset using the same major vein classification as ours. We also found a tradeoff between the cell wall mass per vein length of the major vein and the major vein density. These vein scaling relationships have important implications on the optimization of leaf size, niche differentiation of coexisting species, plant drought tolerance, and species distribution.

Is it necessary to place screws in the intervening vertebrae in two-level anterior cervical discectomy with fusion and plating?

OBJECTIVE: The clinical outcomes, radiological parameters, complication rate and the cost of implants in two-level ACDF with and without screws in the intervening segment were compared. METHODS: A retrospective study of 68 patients who underwent 2-level ACDF from January 2014 to June 2016 was performed. The patients were divided into two groups: ACDF with screws in the intervening vertebra and those without screws in the intervening vertebra. Perioperative factors, clinical outcomes, postoperative complications, radiological parameters, and cost of the implants were evaluated in both groups. RESULTS: No statistical differences in clinical outcomes, operative blood loss, hospital stay, restoration of cervical lordosis or segment height, postoperative complications, and fusion rate were found between the ACDF (middle vertebra with screw) and ACDF (middle vertebra without screw) groups (P > 0.05). But the operative time of added screw placement and cost of implants in the ACDF (middle vertebra without screw) group were significantly less than the ACDF (middle vertebra with screw) group (P < 0.05). CONCLUSION: Two kinds of screw placement with ACDF were found to be similar in terms of clinical outcomes. However, ACDF (middle vertebra without screw) was found to be superior to ACDF (middle vertebra with screw) in terms of the screw placement time and cost of implants.

Repair of bone defect of the lateral forefoot by double segment triangular fibula flap with vascular pedicle: A case report.

Objective: To expound the clinical effect of a new operation by transplanting double segment triangular fibula flap with vascular pedicle to repair the forefoot with lateral bone defect, and to study how to improve the operation method in the following stage. Methods: The inclusion criteria: More than 2 phalangeal and metatarsal bones defects of the lateral forefoot, widespread skin and soft tissue defects on pelma and dorsal foot, and destruction of the anterior aspect of foot arch, which seriously affects the foot function. There was one case of clinical application in November 2014. The repairing method is as followed: the harvested vascularized free fibula was cut into 2 segments and then they were folded into a right angle. According to selected control points on the residual metatarsals, an optimal stereo triangular net was constructed. Meanwhile, according to flow-through mode, the free anterolateral thigh flap was incorporated to repair the forefoot and foot arch. Results: Postoperative bone flaps all survived. After a 17-month following up, it was found that the grafted fibular healed well, shape of the foot was good, weight-bearing walking was practical, a slight limp and discomfort with plantar pain existed, sensory recovery reached S3 level and functional recovery of weight-bearing walking by forefoot reached W3 level, comprehensive evaluation was good, and there were wear scar and ulcer on the plantar flap during long-time walking for patients, such results were excellent according to foot function scoring criteria. Conclusion: In this operation the grafted fibula was fold into a triangle according to actual need, which though not completely restores the tridimensional structure of the longitudinal, transverse arches of the lateral foot makes weight-bearing walking possible, besides, its appearance and function is satisfactory. Such an operation has overcome the shortage of non-tridimensional structure of the transverse arch etc. in traditional operations and it should be an ideal operation in repairing serious defects on the lateral forefoot through further improvement.