Non-destructive measurement technique for water content in organic solvents based on a thermal approach

The water content of organic solvents is one of the crucial properties that affect the quality of the products and the efficiency of the manufacturing processes. The established water determination methods such as Karl Fischer titration and gas chromatography require skilled operators, specific reagents, and prolonged measurement time. Thus, they are not suitable for both on-line and in-line applications. In this study, we aim to develop a real-time and low-cost device with reliable accuracy. The proposed device based on a newly developed thermal approach could non-destructively detect the water content in multiple organic solvents at low concentrations with high accuracy and without the use of any specific reagent. Experiments were performed for the determination of water content in organic solvents such as methanol, ethanol, and isopropanol. The results show that the proposed device is feasible for the water content determination in methanol, ethanol, and isopropanol at 0–1% w/w. A Bland–Altman plot to illustrate the differences in measurements between the proposed device and coulometric Karl Fischer titration shows that most of the measurements lie within the limits of agreement where 95% of the differences between the two methods are expected to fall in the range of −0.13% and 0.09%.

The proposed device could non-destructively detect the water content in organic solvents at low concentrations with high accuracy and without any specific reagent. It could determine the water content in methanol, ethanol, and isopropanol at 0–1% w/w.     

Scalable synthesis of favipiravir via conventional and continuous flow chemistry

Decagram scale synthesis of favipiravir was performed in 9 steps using diethyl malonate as cheap starting material. Hydrogenation and bromination steps were achieved by employing a continuous flow reactor. The synthetic process provided a total of 16% yield and it is suitable for larger-scale synthesis and production.

Decagram scale synthesis of favipiravir was performed in 9 steps using diethyl malonate as cheap starting material.     

Clinical Features,Risk Factors,and Treatments of Microsporidial Epithelial Keratitis

Objective: To report the clinical manifestations, risk factors, and treatments of microsporidial epithelial keratitis in Thailand. Methods: Twenty eyes of 19 patients were diagnosed and the clinical presentations, risk factors, and management were analyzed. Results: Of 19 patients, six patients (32%) had no apparent risk factors. Predisposing factors included soil exposure (6/19, 32%), water contamination (6/19, 32%), and eye liner (1/19, 4%). Twelve cases (63%) were detected in the rainy season. All cases presented with disseminated, punctated, elevated, epithelial keratitis. Corneal scrapings with Gram-chromotrope staining were positive in all patients. Moxifloxacin 0.5% eye drops were given and all 16 patients experienced complete resolution. Three recurrent cases were resolved with only topical moxifloxacin without corneal scraping or swabbing. Conclusions: Predisposing factors were not found in some patients; thus, corneal scraping with staining should be considered in cases having a high index of suspicion. The incidence is increased during the rainy season; therefore, clinicians should have more awareness during these times. Debridement with topical moxifloxacin eye drops, without any systemic medication, may be an effective treatment. Corneal scraping or swabbing may not be required in recurrences.     

Sudden Visual Loss and Total Ophthalmoplegia after Brain Surgery

A 19-year-old woman underwent an occipital craniotomy for removal of a left intraventricular glioblastoma under general anaesthesia and in prone position. Postoperatively she complained of blindness of the right eye. Ocular examination revealed mild proptosis and total ophthalmoplegia of the right eye. Computerized tomography (CT) of the orbits revealed right exophthalmos and enlargement of the extraocular muscles without optic nerve compression. CT angiography showed dilated right supraorbital and supratrochlear arteries without evidence of emboli. Treatment with intravenous methylprednisolone and oral acetazolamide was given. The ocular motility defect improved but the visual loss persisted. As has been emphasized in many similar situations adequate intra-operative ocular protection may reduce such complications.     

Conjunctivitis: Systematic Approach to Diagnosis and Therapy

Conjunctivitis is a common problem in primary health care. Inflammation of the conjunctiva may result from infection or noninfectious causes. Microbial conjunctivitis may be caused by bacteria, viruses, or parasites. Although usually a benign, self-limited disease in healthy individuals, serious complications (eg, keratitis) may be sight-threatening. Accurate diagnosis and specific treatment of conjunctivitis remain challenging. History taking and physical examination are occasionally insufficient for correct diagnosis, thus laboratory testing may play a vital role in identification of specific pathogen(s). However, diagnostic testing has several limitations, including time-consuming methods, increased cost, and requirement for expertise in performance and interpretation. Treatment with empirical topical antibiotics for suspected infectious conjunctivitis is controversial. Although antibiotic treatment can diminish risk of adverse events and shorten the course of disease, drug resistance, toxicity, and expense are important considerations in management of acute infectious conjunctivitis.     

Effect of Eyelid Margin Cleaning on Conjunctival and Eyelid Bacterial Flora Before Intraocular Surgery

Purpose: To compare the bacterial cultures of the lower eyelid margins and lower fornices between ocular irrigations with and without eyelid margin cleaning before intraocular surgery.

Methods: A prospective study was carried out that included 102 eyes from 51 patients undergoing intraocular surgery between December 2016 and April 2017. In each patient, the surgical eye (control group) only received ocular irrigation and the opposite eye (study group) received ocular irrigation with eyelid margin cleaning. Normal saline solution was used in all procedures. In each group, samples from the lower eyelid margins and lower fornices were cultured before and after cleaning. Povidone iodine and antibiotic eye drops were instilled after specimen collection.

Results: The most common bacterial isolate of all groups was Staphylococcus spp. There were no statistically significant differences of positive cultures between the control and study groups in either lower eyelid margins (Odds ratio [OR], 2.19; 95% CI, 0.84–5.72) nor lower fornices (OR, 0.93; 95% CI, 0.43–2.00). In addition, there were no statistically significant differences of positive cultures between before and after eyelid cleanings from both lower eyelid margins (OR, 2.74; 95% CI, 0.53–14.24) and lower fornices (OR, 0.73; 95% CI, 0.21–2.57).

Conclusions: Eyelid margin cleaning with normal saline solution immediately before intraocular surgery did not help to decrease microbial loading on the ocular surfaces. The rate of bacterial contamination, however, was not increased which could be due to not performing eyelid compression.