The On-Orbit Performance of the Galaxy Evolution Explorer

We report the first year on-orbit performance results for the Galaxy Evolution Explorer (GALEX), a NASA Small Explorer that is performing a survey of the sky in two ultraviolet bands. The instrument comprises a 50 cm diameter modified Ritchey-Chretien telescope with a 1.25 degree field of view, selectable imaging and objective grism spectroscopic modes, and an innovative optical system with a thin-film multilayer dichroic beam splitter that enables simultaneous imaging by a pair of photon counting, microchannel plate, delay line readout detectors. Initial measurements demonstrate that GALEX is performing well, meeting its requirements for resolution, efficiency, astrometry, bandpass definition and survey sensitivity.Comment: This paper will be published as part of the Galaxy Evolution Explorer (GALEX) Astrophysical Journal Letters Special Issu

Control Systems for the Mars Pathfinder Mission

The Mars Pathfinder Project began in October 1993, along with the Near Earth Asteroid Rendezvous Program, as one of the first Discovery Program missions funded by NASA. The Mars Pathfinder Project is planned, designed, launched and operated by JPL Mars Pathfinder Project Team under the management of JPL Mars Exploration Project Office. The project is intended to be JPL\u27s most visible demonstration of a successful better, faster, cheaper mission in accordance with NASA\u27s new direction. Mars Pathfinder will place a lander vehicle and rover on the Mars Surface and conduct significant technology and science experiments. The principle mission objective is to demonstrate a low cost cruise, entry, descent and landing system required to place a single payload on the Martian surface in a safe operational mode. Additional objectives include the deployment and operation of three science instruments and operation of the Microrover Flight Experiment. Mars Pathfinder will set the course for future Mars lander missions as part of a comprehensive NASA Mars exploration program

Peptide-based hydrogel for enhanced bone repair

Peptide-based hydrogels are widely studied and applied in bone repair because of their good biocompatibility, biodegradability and designability. Peptide-based hydrogels can be endowed with different properties by introducing biologically functional groups into the peptide chain and adjusting the composition of the peptide-based hydrogels. In addition, in combination with growth factors, cells, and other scaffold materials, the peptide-based hydrogels can meet the needs of bone repair under different conditions. Therefore, we first analyzed the expected properties of peptide-based hydrogels in bone repair and methods to obtain these properties. Then, we focused on the applications in bone repair, especially the repair scheme based on peptide-based hydrogels for different types of bone defects. Peptide-based hydrogels can be used alone to fill bone defects, playing a role in bone conduction. The peptide-based hydrogels can also be used as a sustained-release carrier for cells, drugs, and the like, to improve the microenvironment of local bone regeneration and enhance the bone regeneration capacity. In addition, peptide-based hydrogels can provide solutions for repairing large segmental and weight-bearing bone defects by incorporating other scaffold materials. This review will provide the theoretical basis and cutting-edge design strategies for peptide-based hydrogels to promote the repair of bone defects

Table1_Engineered three-dimensional bioactive scaffold for enhanced bone regeneration through modulating transplanted adipose derived mesenchymal stem cell and stimulating angiogenesis.DOCX

Titanium alloy materials are commonly used in orthopedic clinical treatments. However, conventional titanium implants usually lead to insufficient bone regeneration and integration because of mismatched biomechanics and poor bioactivities. To tackle these challenges, a porous titanium alloy scaffold with suitable mechanical properties was prepared using three-dimensional (3D) printing, and then an adipose-derived mesenchymal stem cell (ADSC) loaded platelet-rich plasma (PRP) gel was placed into the pores of the porous scaffold to construct a bioactive scaffold with dual functions of enhancing angiogenesis and osteogenesis. This bioactive scaffold showed good biocompatibility and supported cell viability proliferation and morphology of encapsulated ADSCs. Osteogenic and angiogenic growth factors in the PRP gel promoted the migration and angiogenesis of human umbilical vein endothelial cells (HUVECs) in vitro and enhanced osteogenic-related gene and protein expression in ADSCs, thus promoting osteogenic differentiation. After implantation into the femoral defects of rabbits, the bioactive scaffold promoted vascular network formation and the expression of osteogenesis-related proteins, thus effectively accelerating bone regeneration. Therefore, the osteogenic and angiogenic bioactive scaffold comprising a 3D printed porous titanium alloy scaffold, PRP, and ADSCs provides a promising design for orthopedic biomaterials with clinical transformation prospects and an effective strategy for bone defect treatment.</p

Image2_Engineered three-dimensional bioactive scaffold for enhanced bone regeneration through modulating transplanted adipose derived mesenchymal stem cell and stimulating angiogenesis.JPEG

Titanium alloy materials are commonly used in orthopedic clinical treatments. However, conventional titanium implants usually lead to insufficient bone regeneration and integration because of mismatched biomechanics and poor bioactivities. To tackle these challenges, a porous titanium alloy scaffold with suitable mechanical properties was prepared using three-dimensional (3D) printing, and then an adipose-derived mesenchymal stem cell (ADSC) loaded platelet-rich plasma (PRP) gel was placed into the pores of the porous scaffold to construct a bioactive scaffold with dual functions of enhancing angiogenesis and osteogenesis. This bioactive scaffold showed good biocompatibility and supported cell viability proliferation and morphology of encapsulated ADSCs. Osteogenic and angiogenic growth factors in the PRP gel promoted the migration and angiogenesis of human umbilical vein endothelial cells (HUVECs) in vitro and enhanced osteogenic-related gene and protein expression in ADSCs, thus promoting osteogenic differentiation. After implantation into the femoral defects of rabbits, the bioactive scaffold promoted vascular network formation and the expression of osteogenesis-related proteins, thus effectively accelerating bone regeneration. Therefore, the osteogenic and angiogenic bioactive scaffold comprising a 3D printed porous titanium alloy scaffold, PRP, and ADSCs provides a promising design for orthopedic biomaterials with clinical transformation prospects and an effective strategy for bone defect treatment.</p

Image1_Engineered three-dimensional bioactive scaffold for enhanced bone regeneration through modulating transplanted adipose derived mesenchymal stem cell and stimulating angiogenesis.JPEG

Titanium alloy materials are commonly used in orthopedic clinical treatments. However, conventional titanium implants usually lead to insufficient bone regeneration and integration because of mismatched biomechanics and poor bioactivities. To tackle these challenges, a porous titanium alloy scaffold with suitable mechanical properties was prepared using three-dimensional (3D) printing, and then an adipose-derived mesenchymal stem cell (ADSC) loaded platelet-rich plasma (PRP) gel was placed into the pores of the porous scaffold to construct a bioactive scaffold with dual functions of enhancing angiogenesis and osteogenesis. This bioactive scaffold showed good biocompatibility and supported cell viability proliferation and morphology of encapsulated ADSCs. Osteogenic and angiogenic growth factors in the PRP gel promoted the migration and angiogenesis of human umbilical vein endothelial cells (HUVECs) in vitro and enhanced osteogenic-related gene and protein expression in ADSCs, thus promoting osteogenic differentiation. After implantation into the femoral defects of rabbits, the bioactive scaffold promoted vascular network formation and the expression of osteogenesis-related proteins, thus effectively accelerating bone regeneration. Therefore, the osteogenic and angiogenic bioactive scaffold comprising a 3D printed porous titanium alloy scaffold, PRP, and ADSCs provides a promising design for orthopedic biomaterials with clinical transformation prospects and an effective strategy for bone defect treatment.</p

Expression and characterization of a Talaromyces marneffei

Phospholipase B is a virulence factor for several clinically important pathogenic fungi, including Candida albicans, Cryptococcus neoformans and Aspergillus fumigatus, but its role in the thermally dimorphic fungus Talaromyces marneffei remains unclear. Here, we provide the first report of the expression of a novel phospholipase gene, designated TmPlb1, from T. marneffei in the eukaryotic expression system of Pichia pastoris GS115. Sensitive real-time quantitative reverse-transcription PCR (qRT-PCR) demonstrated that the expression of TmPlb1 increased 1.85-fold in the yeast phase compared with the mycelial phase. TmPlb1 contains an open reading frame (ORF) of 732 bp that encodes a protein of 243 amino acids. The conserved serine, aspartate and histidine catalytic triad and the G-X-S-X-G domain of TmPLB1 provide the structural basis for its molecular activity. The ORF of TmPlb1 was successfully cloned into a pPIC9K vector containing an α-mating factor secretion signal that allowed the secretory expression of TmPLB1 in P. pastoris. The heterologous protein expression began 12 h after methanol induction and peaked at 96 h. Through analysis with SDS–polyacrylamide gel electrophoresis (SDS-PAGE), western blotting and mass spectrometry, we confirmed that TmPLB1 was successfully expressed. Through Ni-affinity chromatography, TmPLB1 was highly purified, and its concentration reached 240.4 mg/L of culture medium. With specific substrates, the phospholipase A1 and phospholipase A2 activities of TmPLB1 were calculated to be 5.96 and 1.59 U/mg, respectively. The high purity and activity of the TmPLB1 obtained here lay a solid foundation for further investigation