Structural synthetic biology strategy for the design of a new metabolic pathway

To date, notable successes have been made in producing valuable chemicals and fuels from renewable resources by simply modifying and optimizing the metabolic pathways in microorganisms. However, to design a more efficient and desirable pathway with high efficiency from ubiquitously existing multi-branched and multi-level regulated ones, a new approach is needed other than conventional systematic analysis of every bottlenecks embedded in the biosynthetic pathways. Here, we present a strategy combining rational enzyme design and synthetic biology to construct a new metabolic pathway which evades from the highly regulated nature. As a proof-of-concept, we implemented our approach to the design of a new L-methionine biosynthetic pathway. To this end, structure of the MetZ enzyme, which is a key to the construction of new biosynthetic pathway in Corynebacterium glutamicum, was modelled, and its substrate specificity was rationally altered toward a substrate required for redirecting the metabolic flux in the pathway. Furthermore, we used mutational approach to relieve feedback inhibition of other enzymes which regulate the metabolic flux in the methionine biosynthetic pathway. As a result, the L-methionine level reached a gram scale in flask culture by recombinant Corynebacterium glutamicum with the methionine biosynthetic pathway. We demonstrate that the “structural synthetic biology” strategy can boost our ability to generate a more efficient metabolic pathway for the production of valuable chemicals

Highly efficient active optical interconnect incorporating a partially chlorinated ribbon POF in conjunction with a visible VCSEL

A low-loss 4-ch active optical interconnect (AOI) enabling passive alignment was proposed and built resorting to a transmitter (Tx) incorporating a red 680-nm VCSEL, which is linked to a receiver (Rx) module via a partially chlorinated ribbon POF. The POF was observed to exhibit an extremely low loss of similar to 0.24 dB/m at lambda = 680 nm, in comparison to similar to 1.29 dB/m at lambda = 850 nm, and a large numerical aperture of similar to 0.42. Both the Tx and Rx, which taps into a beam router based on collimated beam optics involving a pair of spherical lenses, were meant to be substantially alignment tolerant and compact. The achieved tolerance for the constructed modules was beyond 40 m in terms of the positioning of VCSEL and photodetector. The proposed AOI was completed by linking the Tx with the Rx via a 3-m long ribbon POF, incurring a transmission loss of as small as 3.2 dB. The AOI was practically assessed in terms of a high-speed data transmission over a wide range of temperatures and then exploited to convey full HD video signals. (C) 2014 Optical Society of Americ

EFFECTS OF MO, CR, AND V ADDITIONS ON TENSILE AND CHARPY IMPACT PROPERTIES OF API X80 PIPELINE STEELS

In this study, four API X80 pipeline steels were fabricated by varying Mo, Cr, and V additions, and their microstructures and crystallographic orientations were analyzed to investigate the effects of their alloying compositions on tensile properties and Charpy impact properties. Because additions of Mo and V promoted the formation of fine acicular ferrite (AF) and granular bainite (GB) while prohibiting the formation of coarse GB, they increased the strength and upper-shelf energy (USE) and decreased the energy transition temperature (ETT). The addition of Cr promoted the formation of coarse GB and hard secondary phases, thereby leading to an increased effective grain size, ETT, and strength, and a decreased USE. The addition of V resulted in a higher strength, a higher USE, a smaller effective grain size, and a lower ETT, because it promoted the formation of fine and homogeneous of AF and GB. The steel that contains 0.3 wt pct Mo and 0.06 wt pct V without Cr had the highest USE and the lowest ETT, because its microstructure was composed of fine AF and GB while its maintained excellent tensile properties.X1126sciescopu

Optimization of a Heterogeneous Reaction System for the Production of Optically Active D-Amino Acids Using Thermostable D-Hydantoinase

Abstract: A thermostable D-hydantoinase from Bacillus stearothermophilus SD-1 was previously mass-produced by batch cultivation of the recombinant E. coli harboring the gene encoding the enzyme . In this work, we attempted to optimize the process for the production of N-carbamoyl-D-p-hydroxyphenylglycine, which is readily hydrolyzed to D-p-hydroxyphenylglycine under acidic conditions, from 5-(4-hydroxyphenyl)hydantoin using the mass-produced D-hydantoinase. In an effort to overcome the low solubility of the substrate, enzyme reaction was carried out in a heterogeneous system consisting of a high substrate concentration up to 300 g/L. In this reaction system, most of substrate is present in suspended particles. Optimal temperature and pH were determined to be 45°C and 8.5, respectively, by taking into account the reaction rate and conversion yield. When the free enzyme was employed as a biocatalyst, enzyme loading higher than 300 unit/g-substrate was required to achieve maximum conversion. Use of whole cell enzyme resulted in maximum conversion even at lower enzyme loadings than the free enzyme, showing 96% conversion yield at 300 g/L substrate. The heterogeneous reaction system used in this work might be applied to the enzymatic production of other valuable compounds from a rarely water-soluble substrate

Nasopharynx as a Microbiologic Reservoir in Chronic Suppurative Otitis Media: Preliminary Study

ObjectivesThe present study was designed to identify the correlations of bacterial strains of the middle ear and the nasopharynx in chronic suppurative otitis media (CSOM) patients who were scheduled for operations.MethodsSixty-three patients with CSOM were enrolled in the study. Culture specimens were collected from the middle ear and nasopharynx of patients who were admitted for operation. Samples collections were performed 3 times; from the middle ear and nasophaynx at the admission day, from the middle ear during the operation, and from the external auditory canal post-operatively. Bacteria were identified by gram staining and biochemical tests. The correspondence rate of organisms which simultaneously exist in the middle ear and the nasopharynx was measured.ResultsSixty-eight organisms were isolated from the middle ear and 57 organisms from the nasopharynx among 63 patients. Of 68 bacteria identified in middle ear, 26.52% (18 bacteria) corresponded with those of nasopharynx. MRSA had the high correspondence rate, and of 18 methicillin-resistant Staphylococcus aureus (MRSA) isolated from middle ear, 33.3% (6 bacteria) corresponded with nasophaynx. Meanwhile, 3 organisms of MRSA were detected from the external auditory canal post-operatively, although they were only found in nasopharynx pre-operatively.ConclusionThe current trend of middle ear swab alone for bacterial detection would be insufficient to identify the potent MRSA and impede early antibiotic intervention for the effective middle ear surgery. Therefore, it is necessary to perform nasopharynx cultures together with conventional middle ear culture to control potent risk for infection pre-operatively

Automatic Three-Dimensional Cephalometric Annotation System Using Three-Dimensional Convolutional Neural Networks

Background: Three-dimensional (3D) cephalometric analysis using computerized tomography data has been rapidly adopted for dysmorphosis and anthropometry. Several different approaches to automatic 3D annotation have been proposed to overcome the limitations of traditional cephalometry. The purpose of this study was to evaluate the accuracy of our newly-developed system using a deep learning algorithm for automatic 3D cephalometric annotation. Methods: To overcome current technical limitations, some measures were developed to directly annotate 3D human skull data. Our deep learning-based model system mainly consisted of a 3D convolutional neural network and image data resampling. Results: The discrepancies between the referenced and predicted coordinate values in three axes and in 3D distance were calculated to evaluate system accuracy. Our new model system yielded prediction errors of 3.26, 3.18, and 4.81 mm (for three axes) and 7.61 mm (for 3D). Moreover, there was no difference among the landmarks of the three groups, including the midsagittal plane, horizontal plane, and mandible (p>0.05). Conclusion: A new 3D convolutional neural network-based automatic annotation system for 3D cephalometry was developed. The strategies used to implement the system were detailed and measurement results were evaluated for accuracy. Further development of this system is planned for full clinical application of automatic 3D cephalometric annotation

Ultrasound of the Urinary Bladder, Revisited

Urine-filled bladder can be evaluated easily with ultrasound, and bladder tumors are usually well shown at ultrasound. Although ultrasound is not a primary imaging modality for staging of bladder tumors, it can provide general information regarding depth of tumor invasion into the proper muscle or perivesical adipose tissue. Ultrasound is also useful in showing nonneoplastic lesions of the bladder, such as stone, cystitis, diverticulum and ureterocele. Color Doppler ultrasound can show vascularity of the tumor. It also shows urine flow from the ureteral orifice or through the diverticular neck. As compared with transabdominal ultrasound, transrectal ultrasound shows bladder lesions more markedly in the dorsal wall or neck of the bladder

EFFECT OF LOW DOSE RADIATION ON DIFFERENTIATION OF BONE MARROW CELLS INTO DENDRITIC CELLS

Low dose radiation has been shown to be beneficial to living organisms using several biological systems, including immune and hematopoietic systems. Chronic low dose radiation was shown to stimulate immune systems, resulting in controlling the proliferation of cancer cells, maintain immune balance and induce hematopoietic hormesis. Since dendritic cells are differentiated from bone marrow cells and are key players in maintaining the balance between immune activation and tolerance, it may be important to further characterize whether low dose radiation can influence the capacity of bone marrow cells to differentiate into dendritic cells. We have shown that bone marrow cells from low dose- irradiated (γ-radiation, 0.2Gy, 15.44mGy/h) mice can differentiate into dendritic cells that have several different characteristics, such as expression of surface molecules, cytokine secretion and antigen uptake capacity, when compared to dentritic cells differentiated from the control bone marrow cells. These differences observed in the low dose radiation group can be beneficial to living organisms either by activation of immune responses to foreign antigens or tumors, or maintenance of self-tolerance. To the best of our knowledge, this is the first report showing that total-body low dose radiation can modulate the capacity of bone marrow cells to differentiate into dendritic cells

Arterial Injury Associated with Tension-Free Vaginal Tapes-SECUR Procedure Successfully Treated by Radiological Embolization

Various postoperative complications have been reported after the use of tension-free vaginal tapes (TVT). The transobturator approach was introduced to minimize the potential complications. The next generation of recently introduced TVT-SECUR is intended to minimize the incidence of complications. Herein we report a case of internal pudendal artery injury sustained during this procedure that was successfully treated by radiological embolization. Angiography with vessel embolization, when available, should be considered when the arterial injury is suspected

A Surgically Treated Case of Chronic Necrotizing Aspergillosis with Pleural Invasion

Aspergillus is a ubiquitous fungus and can cause many levels of disease severity. Chronic necrotizing aspergillosis is a rare disease and few cases have been reported in Korea. We experienced a case of pleural aspergillosis that was treated successfully with medical and surgical interventions. The 52-year-old man who was diagnosed with chronic necrotizing pulmonary aspergillosis underwent surgical treatment including a lobectomy, decortication, and myoplasty. The patient was also medically treated with amphotericin B followed by voriconazole. Pleural irrigation with amphotericin B was also performed. A multi-dimensional approach should be considered for treating chronic necrotizing pulmonary aspergillosis