Graphene-Based Strain Sensing of Cementitious Composites with Natural and Recycled Sands.

Structural health monitoring is crucial for ensuring the safety and reliability of civil infrastructures. Traditional monitoring methods involve installing sensors across large regions, which can be costly and ineffective due to the sensors damage and poor compliance with structural members. This study involves systematically varying the graphene nanoplatelets (GNPs) concentration and analyzing the strength performance and piezoresistive behavior of the resulting composites. Two different composites having natural and recycled sands with varying percentages of GNPs as 2%, 4%, 6%, and 8% were prepared. Dispersion of GNPs was performed in superplasticizer and then ultrasonication was employed by using an ultrasonicator. The four-probe method was utilized to establish the piezoresistive behavior. The results revealed that the compressive strength of mortar cubes with natural sand was increased up to a GNP content of 6%, beyond which it started to decline. In contrast, specimens with recycled sand showed a continuous decrease in the compressive strength. Furthermore, the electrical resistance stability was observed at 4% for both natural and recycled sands specimens, exhibiting linearity between the frictional change in the resistivity and compressive strain values. It can be concluded from this study that the use of self-sensing sustainable cementitious composites could pave their way in civil infrastructures.

Pre-operative antibiotic use reduces surgical site infection.

OBJECTIVE: To assess the efficacy of World Health Organisation Surgical Safety Checklist as a simple, reliable and effective tool to ensure appropriate administration of intravenous antibiotics. METHODS: The prospective interventional study was conducted in three phases at Mayo Hospital, Lahore, from May 2011 to January 2012. The first phase comprised baseline data collection, followed by implementation of World Health Organisation Surgical Safety Checklist, and finally post-implementation data collection. The duration of each phase was 3 months. Primary end points were discharge from hospital, 30 days or death of the patient. RESULTS: Of the 613 patients in the study, 303(49.4%) were in the pre-implementation phase and 310(50.5%) in post-implementation phase. Adherence of optimal administration of antibiotic increased from 114(37.6%) to 282(91%) (p<0.001). The rate of post-operative infection fell from 99(32.7%) to 47(15.2%) (p<0.001). Mean hospital stay was reduced from 7.8±5.7 days to 6.5±5.6 days (p<0.001). CONCLUSIONS: Appropriate and timely administration of antibiotic reduced surgical site infection by more than half. Hospital stay was shortened by 1.3 days on average which results in considerable reduction in morbidity, mortality and costs.

Modified Limberg's flap versus primary closure for treatment of pilonidal sinus disease: a comparative study.

OBJECTIVES: To compare the outcome of Rhomboid excision and Modified Limberg's flap closure with excision and primary closure for the treatment of Sacrococcygeal Pilonidal sinus. METHODS: The study was conducted at the Surgical Department of Mayo Hospital, Lahore, from 2009 to 2012. A total of 60 patients of pilonidal sinus were randomly divided into two equal groups. The patients were operated under general anaesthesia in prone position by Rhomboid excision and Modified Limberg's flap closure with a closed suction drain in group 1, and excision and primary closure over a drain in group 2. Patients were followed up for 12 months for surgical complications of the treatment. SPSS 17 was used for statistical analysis. RESULTS: In group 1 there were 27(90%) males and 3(10%) females, while group 2 had 28(93.3%) males and 2(6.7%) females. The infection rates were observed to be 2(7%) in group 1 and 8(26.6%) (p<0.038) in group 2. The recurrence rate was only 1(3.3%) in group 1 compared to 4(13.3%) in group 2. Average hospital stay was 1.63±0.67 days group 1 and 2.8±1.24 days in group 2. CONCLUSION: Modified Limberg's flap closure is an effective treatment modality for pilonidal sinus disease with 1.5 times less infection rate, 4 times less recurrence rate and 40% in-hospital time.

Effect of diet on serotonergic neurotransmission in depression.

Depression is characterized by sadness, purposelessness, irritability, and impaired body functions. Depression causes severe symptoms for several weeks, and dysthymia, which may cause chronic, low-grade symptoms. Treatment of depression involves psychotherapy, medications, or phototherapy. Clinical and experimental evidence indicates that an appropriate diet can reduce symptoms of depression. The neurotransmitter, serotonin (5-HT), synthesized in the brain, plays an important role in mood alleviation, satiety, and sleep regulation. Although certain fruits and vegetables are rich in 5-HT, it is not easily accessible to the CNS due to blood brain barrier. However the serotonin precursor, tryptophan, can readily pass through the blood brain barrier. Tryptophan is converted to 5-HT by tryptophan hydroxylase and 5-HTP decarboxylase, respectively, in the presence of pyridoxal phosphate, derived from vitamin B(6). Hence diets poor in tryptophan may induce depression as this essential amino acid is not naturally abundant even in protein-rich foods. Tryptophan-rich diet is important in patients susceptible to depression such as certain females during pre and postmenstrual phase, post-traumatic stress disorder, chronic pain, cancer, epilepsy, Parkinson's disease, Alzheimer's disease, schizophrenia, and drug addiction. Carbohydrate-rich diet triggers insulin response to enhance the bioavailability of tryptophan in the CNS which is responsible for increased craving of carbohydrate diets. Although serotonin reuptake inhibitors (SSRIs) are prescribed to obese patients with depressive symptoms, these agents are incapable of precisely regulating the CNS serotonin and may cause life-threatening adverse effects in the presence of monoamine oxidase inhibitors. However, CNS serotonin synthesis can be controlled by proper intake of tryptophan-rich diet. This report highlights the clinical significance of tryptophan-rich diet and vitamin B(6) to boost serotonergic neurotransmission in depression observed in various neurodegenerative diseases. However pharmacological interventions to modulate serotonergic neurotransmission in depression, remains clinically significant. Depression may involve several other molecular mechanisms as discussed briefly in this report.