Comparative Evaluation of Antimicrobial Effectiveness and Compressive Strength in Neem and Lemongrass-Modified Glass Ionomer Cement: An In Vitro Study.

Background Glass ionomer cement (GIC) demonstrates biocompatibility and fluoride ion release, indicating their potential to inhibit a wide range of bacteria, although this remains uncertain. Lemongrass and neem are recognized for their potent antimicrobial activity against numerous pathogenic microorganisms. The objective of the study is to evaluate the antimicrobial effectiveness and compressive strength of GIC modified with neem and lemongrass. Methodology Lemongrass and neem were incorporated into conventional GIC at varying concentrations. Group I - neem-modified GIC (0.5%, 1%, 2%), group II - lemongrass-modified GIC (0.5%, 1%, 2%), and group III (non-modified GIC as a control group). The disk-shaped specimens were then compared to unmodified GIC (control). Antimicrobial effectiveness was assessed using the minimal inhibitory concentration (MIC) assay against Streptococcus mutans and Lactobacillus. Compressive strength was assessed using a Universal Testing Machine, with a crosshead speed set to 0.5 mm per minute. Statistical analysis was conducted with a significance level set at p < 0.05. Results Neem modification displayed superior antimicrobial effectiveness against both Streptococcus mutans and Lactobacillus at all concentrations when compared to the control, with 2% showing the least mean value of 0.262. In contrast, lemongrass modification exhibited a significant difference in effectiveness against Streptococcus mutans but no difference against Lactobacillus. Neem modification demonstrated superior performance compared to lemongrass (p < 0.05). Both modified groups showed no significant impact on compressive strength. Conclusions Neem-modified GIC demonstrated the highest antimicrobial efficacy against Streptococcus mutans and Lactobacillus without altering its compressive strength. This suggests its potential as a promising alternative material in restorative dentistry. Additional in vivo investigations are needed to assess the extended-term effectiveness of the material.

Enhanced response of WO3 thin film through Ag loading towards room temperature hydrogen gas sensor.

This study investigates the enhancement of hydrogen gas-sensing performance by introducing silver (Ag) nanoparticles onto tungsten trioxide (WO3) thin films. Herein, the WO3 thin films are deposited onto SiO2/Si substrates using a sputtering technique and Ag nanoparticles are loaded onto the WO3 surface through a spin coating technique. To evaluate the sensing performance of a hydrogen gas, interdigitated titanium (Ti) electrodes are deposited onto the Ag:WO3 layer. Structural, chemical, and morphological analyses are conducted for both pristine WO3 and Ag:WO3 thin films, followed by the investigation of gas-sensing performance by varying hydrogen gas concentrations from 100 ppm to 300 ppm and operating temperatures between 30 °C and 300 °C. The obtained results demonstrate that Ag:WO3 thin films exhibit a notably enhanced response of 5.08% when exposed to a concentration of 100 ppm of hydrogen gas at room temperature, compared to the pristine WO3 of 3.40%. The fabricated Ag:WO3 sensor exhibits a response time of 3.0 s, a recovery time of 4.5 s, and also demonstrates excellent stability over 45 days period. Finally, with the superior sensitivity and fast response time, the fabricated Ti/Ag:WO3/Ti hydrogen gas sensor test-device can be a potential for improvement of safety from both industrial and environmental perspectives.

Recent advances in development of nanostructured photodetectors from ultraviolet to infrared region: A review.

Herein, we aim to evaluate the photodetector performance of various nanostructured materials (thin films, 2-D nanolayers, 1-D nanowires, and 0-D quantum dots) in ultraviolet (UV), visible, and infrared (IR) regions. Specifically, semiconductor-based metal oxides such as ZnO, Ga2O3, SnO2, TiO2, and WO3 are the majority preferred materials for UV photodetection due to their broad band gap, stability, and relatively simple fabrication processes. Whereas, the graphene-based hetero- and nano-structured composites are considered as prominent visible light active photodetectors. Interestingly, graphene exhibits broad band spectral absorption and ultra-high mobility, which derives graphene as a suitable candidate for visible detector. Further, due to the very low absorption rate of graphene (2%), various materials have been integrated with graphene (rGO-CZS, PQD-rGO, N-SLG, and GO doped PbI2). In the case of IR photodetectors, quantum dot IR detectors prevails significant advantage over the quantum well IR detectors due to the 0-D quantum confinement and ability to absorb the light with any polarization. In such a way, we discussed the most recent developments on IR detectors using InAs and PbS quantum dot nanostructures. Overall, this review gives clear view on the development of suitable device architecture under prominent nanostructures to tune the photodetector performance from UV to IR spectral regions for wide-band photodetectors.

Highly Efficient Rubrene-Graphene Charge-Transfer Interfaces as Phototransistors in the Visible Regime.

Atomically thin materials such as graphene are uniquely responsive to charge transfer from adjacent materials, making them ideal charge-transport layers in phototransistor devices. Effective implementation of organic semiconductors as a photoactive layer would open up a multitude of applications in biomimetic circuitry and ultra-broadband imaging but polycrystalline and amorphous thin films have shown inferior performance compared to inorganic semiconductors. Here, the long-range order in rubrene single crystals is utilized to engineer organic-semiconductor-graphene phototransistors surpassing previously reported photogating efficiencies by one order of magnitude. Phototransistors based upon these interfaces are spectrally selective to visible wavelengths and, through photoconductive gain mechanisms, achieve responsivity as large as 107 A W-1 and a detectivity of 9 × 1011 Jones at room temperature. These findings point toward implementing low-cost, flexible materials for amplified imaging at ultralow light levels.

Multilevel Ultrafast Flexible Nanoscale Nonvolatile Hybrid Graphene Oxide-Titanium Oxide Memories.

Graphene oxide (GO) resistive memories offer the promise of low-cost environmentally sustainable fabrication, high mechanical flexibility and high optical transparency, making them ideally suited to future flexible and transparent electronics applications. However, the dimensional and temporal scalability of GO memories, i.e., how small they can be made and how fast they can be switched, is an area that has received scant attention. Moreover, a plethora of GO resistive switching characteristics and mechanisms has been reported in the literature, sometimes leading to a confusing and conflicting picture. Consequently, the potential for graphene oxide to deliver high-performance memories operating on nanometer length and nanosecond time scales is currently unknown. Here we address such shortcomings, presenting not only the smallest (50 nm), fastest (sub-5 ns), thinnest (8 nm) GO-based memory devices produced to date, but also demonstrate that our approach provides easily accessible multilevel (4-level, 2-bit per cell) storage capabilities along with excellent endurance and retention performance-all on both rigid and flexible substrates. Via comprehensive experimental characterizations backed-up by detailed atomistic simulations, we also show that the resistive switching mechanism in our Pt/GO/Ti/Pt devices is driven by redox reactions in the interfacial region between the top (Ti) electrode and the GO layer.

Can Both Cruciate Ligaments Be Preserved in Knee Arthroplasty? Eight- to Nine-Year Follow-Up of a Bicompartmental Knee Replacement.

Preservation of native knee anatomy may confer improved patient satisfaction, as suggested by patient satisfaction scores in unicondylar versus total knee replacement. Bicompartmental knee replacement (BKR) implants similarly promote native tissue preservation. We retrospectively reviewed 42 consecutive patients who underwent BKR from 2006 to 2007. Outcome measures were evaluated. At an average follow-up of 103 months (range 87-110), 34/42 (81%) of implants survived. Among the retained implants, the Knee Society Score (KSS) grade was excellent in 26/34 (76.5%), good in 5/34 (14.7%), fair in 3/34 (8.8%), and poor in 0/34 (0%) of cases. Midterm results of BKR demonstrated 81% survival and 76% with excellent KSS grading. Despite a 20% revision rate at the short-term follow-up, the retained implants functioned well at the midterm follow-up.

PTH circadian rhythm and PTH target-organ sensitivity is altered in patients with adult growth hormone deficiency with low BMD.

UNLABELLED: AGHD is associated with osteoporosis. We examined PTH circadian rhythmicity and PTH target-organ sensitivity in 23 patients with AGHD with low BMD and 20 patients with AGHD with normal BMD. Patients with low BMD had a blunted nocturnal rise in PTH concentration and reduced PTH target-organ sensitivity compared with patients with normal BMD; these factors may be important in the pathogenesis of AGHD-related osteoporosis. INTRODUCTION: Adult growth hormone deficiency (AGHD) is associated with decreased BMD. Reduced parathyroid gland sensitivity to changes in calcium and reduced PTH target-organ sensitivity may underlie the pathogenesis of AGHD-related osteoporosis. A blunted nocturnal PTH rise has been reported in AGHD and may contribute to the reduction in BMD. We examined the difference in PTH concentration and markers of bone metabolism in patients with AGHD with normal and low BMD. MATERIALS AND METHODS: Forty-three patients with AGHD consented to the study. Twenty-five patients were growth hormone (GH) naïve (GH-N, 13 had BMD femoral neck or lumbar spine T-score < -1.0), and 18 patients had received GH for >2 yr (GH-R, 10 had BMD T-score < -1.0). Patients were hospitalized for 24 h, where blood samples were collected every 0.5 h and urine samples were collected every 3 h for PTH, calcium, phosphate, NcAMP, 1,25-dihydroxyvitamin D [1,25(OH)(2)D], type-I collagen beta C-telopeptide (betaCTX), and procollagen type-I amino-terminal propeptide (PINP). Serum calcium was adjusted for albumin (ACa). RESULTS: Low BMD GH-N and GH-R patients exhibited a reduced nocturnal rise in PTH concentration compared with patients with normal BMD (p < 0.001). GH-N low BMD patients had significantly higher 24-h mean PTH (p < 0.001) than GH-N normal BMD patients, with significantly lower 24-h mean NcAMP, ACa, and 1,25(OH)(2)D (p < 0.01), suggesting a reduction in renal PTH sensitivity. GH-R low BMD patients had significantly lower 24-h mean PTH, NcAMP, ACa, and 1,25(OH)(2)D (p < 0.01) than GH-R normal BMD patients, suggesting reduced renal PTH action. Lower PTH concentration in the presence of lower ACa may reflect reduced sensitivity of the parathyroid calcium-sensing receptor to changes in ACa concentration in the GH-R low BMD patients. CONCLUSIONS: Low BMD in GH-N and GH-R AGHD patients may be a consequence of abnormalities in PTH circadian rhythmicity together with reduced parathyroid gland and target-organ sensitivity. Further studies are needed to determine the potential benefit of therapeutic manipulation of PTH rhythmicity and sensitivity on BMD.