Surface Properties of Laser-Treated Molybdenum Disulfide Nanosheets for Optoelectronic Applications

Alrasheed, Abdullah,Gorham, Justin M.,Tran Khac, Bien Cuong,Alsaffar, Fadhel,DelRio, Frank W.,Chung, Koo-Hyun,Amer, Moh. R. American Chemical Society 2018 ACS APPLIED MATERIALS & INTERFACES Vol.10 No.21

<P>Transition metal dichalcogenide two-dimensional materials have attracted significant attention due to their unique optical, mechanical, and electronic properties. For example, molybdenum disulfide (MoS<SUB>2</SUB>) exhibits a tunable band gap that strongly depends on the numbers of layers, which makes it an attractive material for optoelectronic applications. In addition, recent reports have shown that laser thinning can be used to engineer an MoS<SUB>2</SUB> monolayer with specific shapes and dimensions. Here, we study laser-thinned MoS<SUB>2</SUB> in both ambient and vacuum conditions via confocal μ-Raman spectroscopy, imaging X-ray photoelectron spectroscopy (i-XPS), and atomic force microscopy (AFM). For low laser powers in ambient environments, there is insufficient energy to oxidize MoS<SUB>2</SUB>, which leads to etching and redeposition of amorphous MoS<SUB>2</SUB> on the nanosheet as confirmed by AFM. At high powers in ambient, the laser energy and oxygen environment enable both MoS<SUB>2</SUB> nanoparticle formation and nanosheet oxidation as revealed in AFM and i-XPS. At comparable laser power densities in vacuum, MoS<SUB>2</SUB> oxidation is suppressed and the particle density is reduced as compared to ambient. The extent of nanoparticle formation and nanosheet oxidation in each of these regimes is found to be dependent on the number of layers and laser treatment time. Our results can shed some light on the underlying mechanism of which atomically thin MoS<SUB>2</SUB> nanosheets exhibit under high incident laser power for future optoelectronic applications.</P> [FIG OMISSION]</BR>

Clinical and radiographic features of facial cosmetic materials: A systematic review

Alsufyani Noura,Aldosary Reem,Alrasheed Rasha,Alsufyani Mohammed 대한영상치의학회 2022 Imaging Science in Dentistry Vol.52 No.2

Purpose: The aim of this study was to systematically screen the literature for studies reporting cosmetic material in the oral and maxillofacial complex to shed light on the types of cosmetic materials, their radiographic appearance, and possible complications. Materials and Methods: Five electronic databases were reviewed for eligible studies. The general search terms were “cosmetic,” “filler,” “face,” and “radiograph.” Demographics, material types, clinical and radiographic presentation, and complications were recorded. Results: Thirty-one studies with 53 cases met the inclusion criteria. The mean age was 52.6±15.4 years with a 4 : 3 female-to-male ratio. The most common material was calcium hydroxyapatite (CaHa) (n = 14, 26.4%), found inci- dentally. The materials were generally located within the upper cheek and zygoma (n = 35, 66.0%), radiographically well-defined (n = 44, 83%), and had no effects on the surrounding structures (n = 27, 50.9%). The internal structure was radiopaque (calcification, hyperdensity) for gold wires, CaHa, bone implants, and secondary calcification or ossification. Outdated cosmetic materials or non-conservative techniques were infiltrative, had effects on the surrounding structures, and presented with clinical signs, symptoms, or complications. Conclusion: Conventional radiography, cone-beam computed tomography, and multi-detector computed tomography are useful to differentiate several cosmetic materials. Their magnetic resonance imaging appearance was highly variable. The infrequent inclusion of cosmetic materials in the differential diagnosis implies that medical and dental specialists may be unfamiliar with the radiographic appearance of these materials in the face.

Clinical and radiographic features of facial cosmetic materials: A systematic review

Alsufyani, Noura,Aldosary, Reem,Alrasheed, Rasha,Alsufyani, Mohammed Korean Academy of Oral and Maxillofacial Radiology 2022 Imaging Science in Dentistry Vol.52 No.-

Purpose: The aim of this study was to systematically screen the literature for studies reporting cosmetic material in the oral and maxillofacial complex to shed light on the types of cosmetic materials, their radiographic appearance, and possible complications. Materials and Methods: Five electronic databases were reviewed for eligible studies. The general search terms were "cosmetic," "filler," "face," and "radiograph." Demographics, material types, clinical and radiographic presentation, and complications were recorded. Results: Thirty-one studies with 53 cases met the inclusion criteria. The mean age was 52.6±15.4 years with a 4 : 3 female-to-male ratio. The most common material was calcium hydroxyapatite (CaHa) (n=14, 26.4%), found incidentally. The materials were generally located within the upper cheek and zygoma (n=35, 66.0%), radiographically well-defined (n=44, 83%), and had no effects on the surrounding structures (n=27, 50.9%). The internal structure was radiopaque (calcification, hyperdensity) for gold wires, CaHa, bone implants, and secondary calcification or ossification. Outdated cosmetic materials or non-conservative techniques were infiltrative, had effects on the surrounding structures, and presented with clinical signs, symptoms, or complications. Conclusion: Conventional radiography, cone-beam computed tomography, and multi-detector computed tomography are useful to differentiate several cosmetic materials. Their magnetic resonance imaging appearance was highly variable. The infrequent inclusion of cosmetic materials in the differential diagnosis implies that medical and dental specialists may be unfamiliar with the radiographic appearance of these materials in the face.

The effect of gender, age, and body mass index on the medial and lateral posterior tibial slopes: a magnetic resonance imaging study

( Wazzan S. Aljuhani ),( Salman S. Qasim ),( Abdullah Alrasheed ),( Jumanah Altwalah ),( Mohammed J. Alsalman ) 대한슬관절학회 2021 대한슬관절학회지 Vol.33 No.-

Background: The posterior tibial slope (PTS) is crucial in knee joint stability and in maintaining the natural movement of the knee. An increase in the PTS is associated with various knee pathologic conditions, such as anterior cruciate ligament (ACL) injury and anterior tibial translation (ATT). In the present study, we aimed to establish native medial and lateral PTS values for adult Saudis and to identify any association between PTS and gender, age, and body mass index (BMI). Materials and methods: A total of 285 consecutive, normal, magnetic resonance imaging (MRI) studies of the knee were included in the study. The PTS was measured using the proximal anatomical axis of the tibia. The Kruskal-Wallis test was used to compare the medial and lateral PTS angles between age groups. The difference between the medial and lateral posterior tibial slopes was assessed using the Wilcoxon signed-rank test. The Mann-Whitney U test was performed to compare the medial and lateral PTS angles between men and women. Age, gender, and BMI were analyzed by multivariate linear regression to determine whether they positively predict the medial and lateral PTS angles. Results: The mean physiological medial PTS was 5.86 ± 3.0° and 6.61 ± 3.32°, and the lateral PTS was 4.41 ± 3.35° and 4.63 ± 2.85° in men and women, respectively. This difference showed no statistically significant gender dimorphism (p > 0.05). The medial PTS was significantly larger than the lateral PTS (p < 0.0001). There was no statistically significant difference in the medial and lateral PTS angles between age groups (p > 0.05). Higher BMI was significantly associated with a steeper medial PTS (p = 0.001). Conclusions: This study provided native values for medial and lateral PTS angles in Saudis, which can assist surgeons in maintaining normal knee PTS during surgery. The PTS was not influenced by age. The medial PTS was significantly larger than the lateral PTS in men and women. The PTS showed no significant gender dimorphism. BMI was significantly associated with the medial PTS.

Sentiment Analysis of COVID-19 Vaccination in Saudi Arabia

Sawsan Alowa,Lama Alzahrani,Noura Alhakbani,Hend Alrasheed International Journal of Computer ScienceNetwork S 2023 International journal of computer science and netw Vol.23 No.2

Since the COVID-19 vaccine became available, people have been sharing their opinions on social media about getting vaccinated, causing discussions of the vaccine to trend on Twitter alongside certain events, making the website a rich data source. This paper explores people's perceptions regarding the COVID-19 vaccine during certain events and how these events influenced public opinion about the vaccine. The data consisted of tweets sent during seven important events that were gathered within 14 days of the first announcement of each event. These data represent people's reactions to these events without including irrelevant tweets. The study targeted tweets sent in Arabic from users located in Saudi Arabia. The data were classified as positive, negative, or neutral in tone. Four classifiers were used-support vector machine (SVM), naïve Bayes (NB), logistic regression (LOGR), and random forest (RF)-in addition to a deep learning model using BiLSTM. The results showed that the SVM achieved the highest accuracy, at 91%. Overall perceptions about the COVID-19 vaccine were 54% negative, 36% neutral, and 10% positive.

17-alpha hydroxyprogesterone caproate for the prevention of recurrent preterm birth among singleton pregnant women with a prior history of preterm birth: a systematic review and meta-analysis of six randomized controlled trials

( Saeed Baradwan ),( Sahar Hassan Abdulghani ),( Mohammed Abuzaid ),( Khalid Khadawardi ),( Majed Saeed Alshahrani ),( Abdulrahman Al-matary ),( May A. Alrasheed ),( Najlaa Talat Miski ),( Aroob Abdul 대한산부인과학회 2021 Obstetrics & Gynecology Science Vol.64 No.6

To perform a systematic review and meta-analysis of all randomized controlled trials (RCTs) that investigated the clinical benefits of 17-alpha hydroxyprogesterone caproate (17OHPC) in the prevention of recurrent preterm birth (PTB) among singleton pregnant women with a previous history of PTB. We searched four major databases up till April 2021 and assessed the risk of bias in the included studies. We meta-analyzed various maternal-neonatal endpoints (n=18) and pooled them as mean difference or risk ratio (RR) with 95% confidence interval (CI) using the random-effects model. Six RCTs met the inclusion criteria, comprising 2,573 patients (17OHPC=1,617, control=956). RCTs revealed an overall low risk of bias. The rates of PTB <35 weeks (n=5 RCTs; RR, 0.77; 95% CI, 0.63-0.93; P=0.008), PTB <32 weeks (n=3 RCTs; RR, 0.68; 95% CI, 0.51-0.91; P=0.009), neonates with low birth weight (<2.5 kg) at delivery (n=3 RCTs; RR, 0.63; 95% CI, 0.5-0.79; P<0.001), and neonatal death (n=4 RCTs; RR, 0.41; 95% CI, 0.20-0.84; P=0.02) were significantly reduced in the 17OHPC group compared with the control group. Moreover, 17OHPC treatment correlated with a significantly decreased rate of retinopathy (n=2 RCTs; RR, 0.42; 95% CI, 0.18-0.97; P=0.004). However, there were no significant differences in the rates of neonatal intensive care unit admission, cesarean delivery, and other pretermrelated complications between both the groups. Among singleton pregnant women with a prior history of PTB, 17OHPC may favorably decrease the risks of recurrent PTB and reduce the rate of neonatal death.