Current Trends in Acetins Production: Green versus Non-Green Synthesis.

To utilize excess glycerol produced from the biodiesel industry, researchers are developing innovative methods of transforming glycerol into value-added chemicals. One strategy adopted is the conversion of glycerol into acetins, which are esters of glycerol that have wide applications in cosmetics, pharmaceuticals, food and fuel additives, and plasticizers and serve as precursors for other chemical compounds. Acetins are synthesized either by traditional chemical methods or by biological processes. Although the chemical methods are efficient, productive, and commercialized, they are "non-green", meaning that they are unsafe for the environment and consumers. On the other hand, the biological process is "green" in the sense that it protects both the environment and consumers. It is, however, less productive and requires further effort to achieve commercialization. Thus, both methodologies have benefits and drawbacks, and this study aims to present and discuss these. In addition, we briefly discuss general strategies for optimizing biological processes that could apply to acetins production on an industrial scale.

Analysis of the Mediating Effect of Risk Perception on the Relationship Between Time Perception and Mental Health of College Students During the COVID-19 Epidemic.

Background: COVID-19 has had a wide impact on the mental health of college students. This study aims to explore the relationship between time perception, risk perception, and the mental health of college students during COVID-19 through a questionnaire survey. Subjects: One thousand two hundred and eighteen college students, 449 male and 769 female, who studied online during the COVID-19 epidemic were selected. Methods: Time Perception Scale, Risk Perception Scale, and SCL-90 were used to investigate the relationship using correlation analysis. Results: During the COVID-19 period, mental health problems of college students were widespread, and 65.93% of college students reported moderate to severe mental health problems. The correlation analysis showed that risk perception, time perception, and the mental health of college students were significantly related. Risk perception played a partial mediating role between present enjoyment and mental health, and risk perception played a partial mediating role between future time perception and mental health. Conclusion: In the case of sudden public crises, we should pay close attention to the mental health of college students, adjust their attitude toward the present and the future, and pay attention to their perception of risk so as to improve their mental health level under crisis.

Pashto isolated digits recognition using deep convolutional neural network.

Speech recognition has become one of the most significant parts of human-computer interaction due to emergence of new technologies such as smartphone, smart watch and many modern technologies, therefore the need of an ASR for local languages is felt. The basic aim of this paper is to develop an isolated digits recognition for Pashto language, using deep CNN. The database of Pashto digits from 0 to 9 with 50 utterance for each digits is used. Twenty MFCC features extracted for each isolated digit and fed as input to CNN. The network has been used for the proposed system is deep up to 4 convolutional layers, followed by ReLU and max-pooling layers. The network has been trained on the 50% of data and the rest of the data was used for testing. The total average of 84.17% accuracy was achieved for testing which show 7.32% better performance as compared to existing similar works.

Metabolic engineering of Escherichia coli for production of mixed isoprenoid alcohols and their derivatives.

BACKGROUND: Current petroleum-derived fuels such as gasoline (C5-C12) and diesel (C15-C22) are complex mixtures of hydrocarbons with different chain lengths and chemical structures. Isoprenoids are hydrocarbon-based compounds with different carbon chain lengths and diverse chemical structures, similar to petroleum. Thus, isoprenoid alcohols such as isopentenol (C5), geraniol (C10), and farnesol (C15) have been considered to be ideal biofuel candidates. NudB, a native phosphatase of Escherichia coli, is reported to dephosphorylate isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP) into isopentenol. However, no attention has been paid to its promiscuous activity toward longer chain length (C10-C15) prenyl diphosphates. RESULTS: In this study, the promiscuous activity of NudB toward geranyl diphosphate (GPP) and farnesyl diphosphate (FPP) was applied for the production of isoprenoid alcohol mixtures, including isopentenol, geraniol, and farnesol, and their derivatives. E. coli was engineered to produce a mixture of C5 and C15 alcohols by overexpressing NudB (dihydroneopterin triphosphate diphosphohydrolase) and IspA (FPP synthase) along with a heterologous MVA pathway, which resulted in a total of up to 1652 mg/L mixture of C5 and C15 alcohols and their derivatives. The production was further increased to 2027 mg/L by overexpression of another endogenous phosphatase, AphA, in addition to NudB. Production of DMAPP- and FPP-derived alcohols and their derivatives was significantly increased with an increase in the gene dosage of idi, encoding IPP isomerase (IDI), indicating a potential modulation of the composition of the alcohols mixture according to the expression level of IDI. When IspA was replaced with its mutant IspA*, generating GPP in the production strain, a total of 1418 mg/L of the isoprenoid mixture was obtained containing C10 alcohols as a main component. CONCLUSIONS: The promiscuous activity of NudB was newly identified and successfully used for production of isoprenoid-based alcohol mixtures, which are suitable as next-generation biofuels or commodity chemicals. This is the first successful report on high-titer production of an isoprenoid alcohol-based mixture. The engineering approaches can provide a valuable platform for production of other isoprenoid mixtures via a proportional modulation of IPP, DMAPP, GPP, and FPP syntheses.

Metabolic engineering and synthetic biology approaches driving isoprenoid production in Escherichia coli.

Isoprenoids comprise the largest family of natural organic compounds with many useful applications in the pharmaceutical, nutraceutical, and industrial fields. Rapid developments in metabolic engineering and synthetic biology have facilitated the engineering of isoprenoid biosynthetic pathways in Escherichia coli to induce high levels of production of many different isoprenoids. In this review, the stem pathways for synthesizing isoprene units as well as the branch pathways deriving diverse isoprenoids from the isoprene units have been summarized. The review also highlights the metabolic engineering efforts made for the biosynthesis of hemiterpenoids, monoterpenoids, sesquiterpenoids, diterpenoids, carotenoids, retinoids, and coenzyme Q10 in E. coli. Perspectives and future directions for the synthesis of novel isoprenoids, decoration of isoprenoids using cytochrome P450 enzymes, and secretion or storage of isoprenoids in E. coli have also been included.

Pattern of firearm injuries in head and neck regions at a tertiary care hospital.

OBJECTIVE: To determine the characteristics of firearm injuries on head and neck in patients presenting to the Ear Nose and Throat Department of a tertiary care hospital. METHODS: This prospective, cross-sectional study was conducted at the Lady Reading Hospital, Peshawar, from June 2014 to May 2015, and comprised victims of firearm injuries. They were subjected to a thorough examination of the wounds specifically and the rest of the Ear, Nose and Throat, Head and Neck regions generally. Data was collected on a proforma. SPSS 16 was used for data analysis. RESULTS: Out of the 56 patients, 49(87.5%) were men. The overall mean age was 28.68±1.63 years (range: 6-80 years. Besides, 33(58.9%) patients were in the age range 20-40 years followed by 18(32.1%) below 20 years. Overall, 27(48.2%) patients were jobless and 24(42.9%) had education below grade ten. Pistol was the most commonly-used weapon in 28(50%).Hospital stay was 2-10 days with a mean of 4.37±1.74 days. Single-entry wound on the neck was common 21(37.5%), predominantly on the right side 24(42.9%), while there were 33(58.9%) single-exit wounds, affecting neck in 18(32.1%) cases and on the left side in 19(33.9%). CONCLUSIONS: Firearm injuries were common among young men who were illiterate and poor socioeconomically. Homicidal injuries mostly occurred during the daytime. Pistol was the most commonly-used weapon, while wounds on the neck were more common.

Infantile Fibrosarcoma of Tongue: A Rare Tumor.

Infantile fibrosarcoma is very rare tumor and seldom occurs in oral cavity. Overall good prognosis is reported in more than 80% cases. We present a 5-month old female patient with swelling of the tongue for four months. This was excised completely. Histopathology and immunohistochemistry revealed it as infantile fibrosarcoma of grade II.

Anatomical relationship between recurrent laryngeal nerve and inferior thyroid artery in thyroidectomy patients.

BACKGROUND: Thyroid surgery is performed very frequently now a day. Previously it was used to be associated with high morbidity especially hoarseness. This complication is now almost negligible as most of the surgeons are well acquainted with the anatomical knowledge of the nerves in relation to the gland. The objective of this study was to find out variable anatomical relationships between Recurrent Laryngeal Nerve and Inferior Thyroid Artery in patients undergoing thyroid surgery. METHODS: This cross-sectional retrospective study was conducted in Government Lady Reading Hospital Peshawar and Abasyn Hospital (Private) Peshawar from May 2010 to June 2014. Patients undergoing surgery for benign goiters, T1, T2 well differentiated thyroid cancers without lymph node involvement was included. Data on various types of relationships between RLN and ITA were recorded. RESULTS: In total 271 patients operated and included in the study, 117 were male and 154 were female. Total of 398 RLNs were identified in 416 sides operated. In 55.27% cases the nerve was found to be anterior to inferior thyroid artery while it was posterior to the artery in 34.67% cases. In the remaining 10.05% cases the nerve was observed passing within the branches of inferior thyroid artery. CONCLUSIONS: The anatomical relationship between Recurrent Laryngeal Nerve RLN and Inferior Thyroid Artery ITA is highly variable. For all head and neck surgeons to perform safe surgery on thyroid, it is necessary to have sound anatomical knowledge of these variable relationships between recurrent laryngeal nerve and inferior thyroid artery.

Laser and incisional myringotomy in otitis media with effusion-a comparative study.

BACKGROUND: Otitis media with effusion (OME) or middle ear effusion (MEE) is a common cause of hearing difficulty in children. MEE must be detected early and managed properly to prevent conductive hearing loss in children. It was aimed to compare results of laser myringotomy and conventional myringotomy in terms of hearing improvement, recurrence of MEE and time to put ventilation tube. METHODS: This randomized control trial was conducted from February 2012 to April 2014. Children of 4 years age or older with MEE were included in the study. These children were investigated with Pure tone audiometry (PTA) and tympanometry to confirm conductive hearing loss. X-Ray nasopharynx lateral view was performed for adenoids. Sixty-six patients were randomly assigned in to 2 groups, (1) treated with laser myringotomy and (2) treated with classical myringotomy. The ears were evaluated for MEE, for presence of perforation and level of hearing. RESULTS: A total of 98 ears in 66 patients underwent intervention. Middle ear effusion cleared in 44 out of 48 ears with laser myringotomy (LM) as compared to34 out of 50 ears with incisional myringotomy. The perforation was still patent in 36 ears treated with LM while it was found closed in all 50 ears with conventional myringotomy after 2 weeks. The hearing level improved with LM by 10-15 dB after first 3 months. CONCLUSION: The aim of management in otitis media with effusion is ventilation of tympanic cavity. Laser myringotomy is a best alternative to conventional one. It also has comparable results with ventilation tubes (VT). The ears with refractory or recurrent MEE should have VT insertion.