Tuning of Polymer Nanoparticle Size via Miniemulsion Polymerization using Membrane Emulsification

The implementation of membrane emulsification for the synthesis of polymer nanoparticles via miniemulsion polymerization has been investigated. Miniemulsion polymerization affords an eco-friendly solvent-free route for generating polymer particles directly from monomer droplets generally sized in the 50-500 nm range. Such small droplets can be usually attained through high shear techniques which not only demand high energy input but, also present potential hurdles to the scale-up due to poor droplet size control and reproducibility. Other methods that involve comparatively low energy suffer from poor emulsion stability. In contrast, membrane emulsification provides a low energy emulsification route to the polymer particle synthesis with better size control. The use of the smallest available pore size of 100 nm to prepare miniemulsion would be a true test of the versatility of membrane emulsification. Preparing submicron-sized droplets and particles of methyl methacrylate (MMA) through pore size 100-400 nm, monomodal particle size distributions similar to initial droplets were achieved with the aid of sufficiently hydrophobic initiator (lauroyl peroxide). The implementation of this novel approach for nanoparticle synthesis enables convenient tuning of droplets/particles in the diameter range of 250-1600 nm simply by selecting an appropriate pore size and warranted further investigation. Due to the high water solubility of MMA leading to secondary nucleation issues, the feasibility of other monomers (butyl methacrylate, benzyl methacrylate, n-butyl acrylate, and styrene) based on water solubility was also studied. The comparison showed that stable emulsions were achieved with narrow size distribution for all monomers except styrene. The versatility of membrane emulsification was also explored in combination with continuous synthesis using photoinduced miniemulsion polymerization. Mini/microemulsions generated by membrane emulsification were subjected to visible (violet) light (λmax = 405 nm) at room temperature in a tubular reactor. With careful consideration of surfactant concentration and aqueous phase radical scavenger, high conversions were achieved in 10 min. This body of work expands the scope of current research in the emerging field of membrane emulsification. The innovative approach of tuning the particle size simply by selecting the appropriate pore size provides an interesting perspective for nanoparticle synthesis and will pave the way towards new applications of polymer nanoparticles

Periodontal Treatment Needs of Patients Undergoing Orthodontic Treatment in Comparison To Non-Orthodontic Treatment Patients: A Comparative Study

OBJECTIVES To determine the periodontal treatment needs of patients undergoing orthodontic treatment compared to those not undergoing the treatment.   METHODOLOGY A cross-sectional comparative study was conducted on 100 patients visiting the Dental OPD of Sharif Medical and Dental College, Lahore, from June 2019 to July 2020. Clinical examination was done using the Community Periodontal index for treatment needs (CPITN) to assess the participants' periodontal health and treatment needs. RESULTS There was a statistically significant difference in the scores of CPITN across the treatment and control groups (≤0.001). The patients requiring scaling and prophylaxis and Oral hygiene instructions (TN 2) were more (94%) in the orthodontic treatment group in comparison to the non-orthodontic treatment group (62%). A higher percentage of patients (6%) requiring complex treatment (deep scaling, root planning and complex surgical procedures), scaling and prophylaxis and Oral hygiene instructions (TN3) belonged to the non-orthodontic treatment group, while only 4% required it from the orthodontic treatment group. CONCLUSION All orthodontic and non-orthodontic treatment group participants required oral hygiene instructions and had periodontal treatment needs (TN1). The patients requiring scaling and prophylaxis and Oral hygiene instructions (TN 2) were more in the orthodontic treatment group than the non-orthodontic treatment group. A higher percentage of patients requiring complex treatment (deep scaling, root planning and complex surgical procedures), scaling and prophylaxis and Oral hygiene instructions (TN3) belonged to the non-orthodontic treatment group

Knowledge and Awareness about Cervical Cancer and Its Prevention amongst Interns and Nursing Staff in Tertiary Care Hospitals in Karachi, Pakistan

Cervical cancer is one of the leading causes of morbidity and mortality amongst the gynecological cancers worldwide, especially in developing countries. It is imperative for at least health professionals in developing countries like Pakistan to have a sound knowledge about the disease. This study was carried out to assess the knowledge and awareness about cervical cancer and its prevention amongst health professionals in tertiary care hospitals in Karachi, Pakistan.A cross-sectional, interview based survey was conducted in June, 2009. Sample of 400 was divided between the three tertiary care centers. Convenience sampling was applied as no definitive data was available regarding the number of registered interns and nurses at each center.Of all the interviews conducted, 1.8% did not know cervical cancer as a disease. Only 23.3% of the respondents were aware that cervical cancer is the most common cause of gynecological cancers and 26% knew it is second in rank in mortality. Seventy-eight percent were aware that infection is the most common cause of cervical cancer, of these 62% said that virus is the cause and 61% of the respondents knew that the virus is Human Papilloma Virus (HPV). Majority recognized that it is sexually transmitted but only a minority (41%) knew that it can be detected by PCR. Only 26% of the study population was aware of one or more risk factors. Thirty seven percent recognized Pap smear as a screening test. In total only 37 out of 400 respondents were aware of the HPV vaccine.This study serves to highlight that the majority of working health professionals are not adequately equipped with knowledge concerning cervical cancer. Continuing Medical Education program should be started at the hospital level along with conferences to spread knowledge about this disease

Particle Size Control in Miniemulsion Polymerization via Membrane Emulsification

y Miniemulsion polymerization of methyl methacrylate has been conducted employing Shirasu porous glass (SPG) membrane emulsification for the generation of the initial miniemulsion. For the first time, submicron-sized monomer droplets and polymer particles have been prepared using membranes with pore sizes significantly smaller than those previously reported. Membrane pore sizes of diameters 100-400 nm were explored, demonstrating that the final particle size can be conveniently tuned within the diameter range of 250-1600 nm. The choice of radical initiator is crucial: a sufficiently hydrophobic initiator (lauroyl peroxide) is required to minimize the generation of bimodal particle size distributions via secondary nucleation. Given the advantages of low energy consumption, reduced shear stress (compared with conventional high-energy mixing approaches such as ultrasonication), and an easily adjustable particle size via the membrane pore size, membrane emulsification has significant potential for the synthesis of polymeric nanoparticles via miniemulsion polymerization.The authors acknowledge the European Union Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No. 665501 with the research Foundation Flanders (FWO) (N.Z.)

Mean level of pretreatment neutrophil to lymphocyte ratio in patients with squamous cell carcinoma of the head and neck-cross-sectional study

Background: Squamous cell carcinoma of the head and neck have been characterized using various prognostic parameters. These include advanced age, lifestyle habits such as smoking, higher tumor stage at presentation & presence of metastasis. Many patients are diagnosed with head and neck cancers annually in Pakistan, but limited data is available for the prognosis of these patients. This study aims to investigate a new biomarker by estimating the mean level of pretreatment neutrophil to lymphocyte ratio (NLR) in patients with Squamous cell carcinoma of the head & neck.Methods: We conducted a cross-sectional study using non-probability consecutive sampling techniques for 222 biopsy-proven cases of head & neck squamous cell carcinoma. Clinical & pathological variables were analyzed, including the patient\u27s profile and tumor characteristics. The NLR of each patient before treatment was calculated using the absolute neutrophil count divided by the absolute lymphocyte count in preoperative blood samples. An independent sample t-test was used to assess the mean difference. A p-value less than or equal to 0.05 was taken as statistically significant.Results: Of 222 patients, a male predominance was seen in the entire cohort. A median pretreatment NLR of 3.19 (2.47-4.97) was identified, and patients were classified into high and low NLRs based on this value. Data analysis revealed a statistically significant increase in NLR among patients with nodal metastasis. In addition, patients with NLR above the median cutoff value of 3.19 demonstrated that there was a significant increase in NLR values with high tumor (T) and nodal (N) classifications with a p-value of 0.001 and 0.003, respectively.Conclusion: Pretreatment neutrophil to lymphocyte ratio may be associated with increased nodal involvement. It may serve as a useful prognostic predictor for patients with squamous cell carcinomas of the head and neck. Identifying high-risk patients in the pretreatment phase with the help of such biomarkers will also facilitate early inclusion in clinical trials

Mean level of pretreatment neutrophil to lymphocyte ratio in patients with squamous cell carcinoma of the head and neck–Cross-sectional study

Background: Squamous cell carcinoma of the head and neck have been characterized using various prognostic parameters. These include advanced age, lifestyle habits such as smoking, higher tumor stage at presentation & presence of metastasis. Many patients are diagnosed with head and neck cancers annually in Pakistan, but limited data is available for the prognosis of these patients. This study aims to investigate a new biomarker by estimating the mean level of pretreatment neutrophil to lymphocyte ratio (NLR) in patients with Squamous cell carcinoma of the head & neck. Methods: We conducted a cross-sectional study using non-probability consecutive sampling techniques for 222 biopsy-proven cases of head & neck squamous cell carcinoma. Clinical & pathological variables were analyzed, including the patient's profile and tumor characteristics. The NLR of each patient before treatment was calculated using the absolute neutrophil count divided by the absolute lymphocyte count in preoperative blood samples. An independent sample t-test was used to assess the mean difference. A p-value less than or equal to 0.05 was taken as statistically significant. Results: Of 222 patients, a male predominance was seen in the entire cohort. A median pretreatment NLR of 3.19 (2.47–4.97) was identified, and patients were classified into high and low NLRs based on this value. Data analysis revealed a statistically significant increase in NLR among patients with nodal metastasis. In addition, patients with NLR above the median cutoff value of 3.19 demonstrated that there was a significant increase in NLR values with high tumor (T) and nodal (N) classifications with a p-value of 0.001 and 0.003, respectively. Conclusion: Pretreatment neutrophil to lymphocyte ratio may be associated with increased nodal involvement. It may serve as a useful prognostic predictor for patients with squamous cell carcinomas of the head and neck. Identifying high-risk patients in the pretreatment phase with the help of such biomarkers will also facilitate early inclusion in clinical trials

Knowledge of the respondents regarding the epidemiology and etiology of cervical cancer.

<p>Knowledge of the respondents regarding the epidemiology and etiology of cervical cancer.</p

Percentage distribution of presenting features based on the responses of study population.

<p>Percentage distribution of presenting features based on the responses of study population.</p

Knowledge about HPV – A causative agent for Cervical Cancer.

<p>Knowledge about HPV – A causative agent for Cervical Cancer.</p