Compact System Research Articles

A 3D printing assisted microfluidic absorbance-based measurement system for biological assay

Development of rapid analytical systems utilizing 3D printing is an emerging area of interest with the potential to provide efficient solutions by integrating multidisciplinary technology without compromising the quality of the system. In this study we report the fabrication of a 3D printing assisted microfluidic based absorbance measurement system, leveraging 3D printing along with integrating miniature optical components for the accurate measurement of biological assays. The developed system is rapid, affordable, and compact, through set of computer-aided design models and fusion deposition modeling 3D printing along with relevant electronic circuitry involving optical components like surface mounting devices. The handheld device features a capacitive touchscreen display, programmed to seamlessly perform MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. The device was employed for assessing the cell viability using Michigan cancer foundation-7 (MCF-7) cell lines over varying concentrations of tamoxifen, reciprocating the MTT assay analysis conducted by using spectrophotometer. The device achieved excellent results which upon comparison with the conventional spectrophotometer-based results have shown a correlation coefficient of 0.98. This compact and rapid absorbance measurement system holds significant potential for evaluating the cytotoxicity of drugs, and further development of innovative analytical devices.

The distribution and antibiotic-resistant characteristics and risk factors of pathogens associated with clinical biliary tract infection in humans

IntroductionBiliary Infection in patients is a common and important phenomenon resulting in severe complications and high morbidity, while the distributions and drug resistance profiles of biliary bacteria and related risk factors are dynamic. This study explored the characteristics of and risk factors for biliary infection to promote the rational use of antibiotics in clinically.MethodsBacterial identification and drug susceptibility testing were completed using the Vitek 2 Compact analysis system. The distribution and antibiotic-resistant characteristics of 3,490 strains of biliary bacteria in patients at Nankai Hospital from 2019 to 2021 were analyzed using Whonet 5.6 and SPSS 26.0 software. We then retrospectively analyzed the clinical data and risk factors associated with 2,340 strains of Gram-negative bacilli, which were divided into multidrug-resistant bacteria (1,508 cases) and non-multidrug-resistant bacteria (832 cases) by a multivariate Cox regression model.Results and discussionA total of 3,490 pathogenic bacterial strains were isolated from bile samples, including 2,340 (67.05%) Gram-negative strains, 1,029 (29.48%) Gram-positive strains, and 109 (4.56%) fungal strains. The top five pathogenic bacteria were Escherichia coli, Klebsiella pneumoniae, Enterococcus faecium, Enterococcus faecalis, and Pseudomonas aeruginosa. The rate of Escherichia coli resistance to ciprofloxacin increased (p < 0.05), while the resistance to amikacin decreased (p < 0.05). The resistance of Klebsiella pneumoniae to cephalosporins, carbapenems, β-lactamase inhibitors, cephalases, aminoglycosides, and quinolones increased (p < 0.05), and the resistance of Pseudomonas aeruginosa to piperacillin, piperacillin/tazobactam, ticacillin/clavulanic acid, and amicacin declined significantly (p < 0.05). The resistance of Enterococcus faecium to tetracycline increased by year (p < 0.05), and the resistance of Enterococcus faecalis to erythromycin and high-concentration gentamicin declined (p < 0.05). Multivariate logistic regression analysis suggested that the administration of third- or fourth-generation cephalosporins was an independent risk factor for biliary infection. In summary, Gram-negative bacilli were the most common pathogenic bacteria isolated from biliary infection patients, especially Escherichia coli, and the rates and patterns of drug resistance were high and in constant flux; therefore, rational antimicrobial drug use should be carried out considering risk factors.

Random broadband filters based on combination of metasurface and multilayer thin films for hyperspectral imaging

Metasurface based micro-spectrometer presents a promising avenue for achieving compact, lightweight, and cost-effective solutions for miniaturization of hyperspectral imaging systems. Nevertheless, this type of design encounter limitations primarily due to constrained manipulation mechanism of light field, resulting in high cross-correlation among transmission spectra and imperfect reconstructed images. In this paper, we propose and numerically demonstrate a micro-spectrometer based on metasurface combined with multilayer thin films, whose spectral response improves performance for application, i.e. achieving low spectral cross-correlation. Additionally, we incorporate particle swarm optimization with compressed sensing algorithm to optimize the proposed micro-spectrometer. This approach effectively reconstructs both narrowband and broadband hyperspectral signals with minimal error, achieving an impressive 2 nm spectral resolution. The simulation results of hyperspectral imaging demonstrated that the proposed methodology successfully reconstructs broadband hyperspectral images with an average spectral fidelity of 91.42%. This method holds significant potential for integrating into smartphones and other portable spectrometers, advancing the design of compact hyperspectral imaging systems.

Proteome analysis, genetic characterization, and antibiotic resistance patterns of Klebsiella pneumoniae clinical isolates

Klebsiella pneumoniae (K. pneumoniae) is a member of the ESKAPE group and is responsible for severe community and healthcare-associated infections. Certain Klebsiella species have very similar phenotypes, which presents a challenge in identifying K. pneumoniae. Multidrug-resistant K. pneumoniae is also a serious global problem that needs to be addressed. A total of 190 isolates were isolated from urine (n = 69), respiratory (n = 52), wound (n = 48) and blood (n = 21) samples collected from various hospitals in the Al-Qassim, Saudi Arabia, between March 2021 and October 2022. Our study aimed to rapidly and accurately detect K. pneumoniae using the Peptide Mass Fingerprinting (PMF) technique, confirmed by real-time PCR. Additionally, screening for antibiotic susceptibility and resistance was conducted. The primary methods for identifying K. pneumoniae isolates were culture, Gram staining, and the Vitek® 2 ID Compact system. An automated MALDI Biotyper (MBT) instrument was used for proteome identification, which was subsequently confirmed using SYBR green real-time polymerase chain reaction (real-time PCR) and microfluidic electrophoresis assays. Vitek® 2 AST-GN66 cards were utilized to evaluate the antimicrobial sensitivity of K. pneumoniae isolates. According to our results, Vitek® 2 Compact accurately identified 178 out of 190 (93.68%) K. pneumoniae isolates, while the PMF technique correctly detected 188 out of 190 (98.95%) isolates with a score value of 2.00 or higher. Principal component analysis was conducted using MBT Compass software to classify K. pneumoniae isolates based on their structure. Based on the analysis of the single peak intensities generated by MBT, the highest peak values were found at 3444, 5022, 5525, 6847, and 7537 m/z. K. pneumoniae gene testing confirmed the PMF results, with 90.53% detecting entrobactin, 70% detecting 16 S rRNA, and 32.63% detecting ferric iron uptake. The resistance of the K. pneumoniae isolates to antibiotics was as follows: 64.75% for cefazolin, 62.63% for trimethoprim/sulfamethoxazole, 59.45% for ampicillin, 58.42% for cefoxitin, 57.37% for ceftriaxone, 53.68% for cefepime, 52.11% for ampicillin-sulbactam, 50.53% for ceftazidime, 52.11% for ertapenem, and 49.47% for imipenem. Based on the results of the double-disk synergy test, 93 out of 190 (48.95%) K. pneumoniae isolates were extended-spectrum beta-lactamase. In conclusion, PMF is a powerful analytical technique used to identify K. pneumoniae isolates from clinical samples based on their proteomic characteristics. K. pneumoniae isolates have shown increasing resistance to antibiotics from different classes, including carbapenem, which poses a significant threat to human health as these infections may become difficult to treat.

Dual-parameter controlled reconfigurable metasurface for enhanced terahertz beamforming via inverse design method

Recently, reconfigurable metasurfaces have emerged as a promising solution for wavefront manipulation in the terahertz (THz) region, providing enhanced beamforming capabilities. However, traditional single-parameter control methods fail to achieve independent phase and amplitude modulation, constraining their modulation capabilities. Meanwhile, forward design methods based on phase matching ignore the structural responses of the non-ideal unit, leading to degraded beamforming performance. Here, we introduce an electrically reconfigurable metasurface composed of bilayer graphene strips based on dual-parameter control. Full-wave simulations demonstrate independent amplitude and phase modulation, achieving the full 360° phase coverage and an adjustable amplitude range from 0 to 0.8 at 2.6 THz. To optimize beamforming performance, particularly for the responses of the non-ideal unit away from the designed frequency, we employed an inverse design method based on a hybrid evolutionary algorithm. This novel approach significantly enhances beam steering, achieving a maximum 60% increase in beam directivity and maintaining over 90% of ideal directivity across a broad frequency range from 1.6 THz to 5 THz. Especially, it achieves a maximum deflection angle of 75°. Meanwhile, the adaptability of the inverse design method is further demonstrated to various optimized objectives. For beam focusing, even with limited phase control (below 210°), this method significantly enhances the focusing quality (up to 150% enhancement) and increases the focusing efficiency from 25% to 40%. Additionally, it effectively mitigates the impact of quantized phase errors on beamforming. This research not only demonstrates potential applications in high-speed THz wireless communication and compact imaging systems but also paves the way for innovative designs in reconfigurable metasurfaces.

Anisotropic compact star in linear f(Q)-action

In this paper, a significant leap forward in understanding compact stellar systems and the modified f(Q) gravity theory is achieved. The pivotal discovery lies in the successful derivation of an exact solution that fulfils the static geometry and spherical symmetry criteria, permitting the study of compact stellar configurations with an anisotropic fluid. The model is rigorously tested and satisfies the vital physical conditions within the stellar fluid, guaranteeing its viability. The numerical values of constant parameters have been calculated by using the observational data of the compact star, namely, Her X-1. The equi-mass contours highlight an impressive correlation between the f(Q) gravity parameters. Boosting α while keeping β fixed and concurrently boosting R leads to a significant global boost in mass distribution. This can be ascribed to the enhanced coupling arising from a higher α, which broadens the mass distribution. In addition, the larger object size arising from the rise in R allows for more mass accommodation. Therefore, raising both R and α leads to an exaggerated mass distribution, proving the combined influence of coupling strength and object size on total mass. Altogether, this investigation advances our knowledge of compact stellar systems and supports the evolution of the modified f(Q) theory of gravity, opening the way for more breakthroughs in this field.

Performance of a High-Speed Pyroelectric Receiver as Cryogen-Free Detector for Terahertz Absorption Spectroscopy Measurements

The application of terahertz (THz) radiation in scientific research as well as in applied and commercial technology has expanded rapidly in recent years. One example is the progress in high-resolution THz spectroscopy based on quantum cascade lasers, which has enabled new observations in astronomy, atmospheric research, and plasma diagnostics. However, the lack of easy-to-use and miniaturised detectors has hampered the development of compact THz spectroscopy systems out of the laboratory environment. In this paper, we introduce a new high-speed pyroelectric receiver as a cryogen-free detector for THz absorption spectroscopy. Its performance is characterised by absorption spectroscopy measurements on a reference gas cell (RGC) with ammonia using a tunable THz quantum cascade laser at approximately 4.75 THz as the light source. It is shown that the receiver can record spectra up to 281 Hz without any artefacts to the observed spectral absorption profile, and the results reproduce the known pressure of ammonia in the RGC. This demonstrates that the pyroelectric receiver can be reliably used as an alternative to helium-cooled bolometers for absorption spectroscopy measurements in the THz range, with its main advantages being the high bandwidth, compactness, relatively low cost, and room-temperature operation. Its simplicity and high sensitivity make this receiver a key component for compact THz spectroscopy systems.

Swift X-ray and UV observations of six Gaia binaries supposedly containing a neutron star

Recent observations have led to the discovery of numerous optically selected binaries containing an undetected component with mass consistent with a compact object (neutron star (NS) or white dwarf). Using the Neil Gehrels Swift Observatory, we carried out X-ray and UV observations of a small sample of these binaries. Four systems are wide (with an orbital period P$>300 d$), and were chosen because of their small distance (d$<$250 pc) and because the mass of the collapsed component favors a NS. Two others are compact systems (P$<0.9 d$) that show strong signs of containing a NS. The source 2MASS J15274848$+$3536572 was detected in the X-ray band with a flux of $5 $ erg cm$^ $ s$^ $ and a spectrum well fitted by a power law or a thermal plasma emission model. This source also shows a UV (2200 AA ) excess, which might indicate the presence of mass accretion. For the other targets, we derived X-ray flux upper limits of the order of $10^ $ erg cm$^ $ s$^ $ . These results are consistent with the hypothesis that the collapsed component in these six systems is a NS.

Green Manufacturing of Electrically-Tunable Smart Light-Weight Planar Optics: A Review

AbstractEvolving demands for compact, light-weight, and versatile optical systems across various industries require the facile integration of planar diffractive optics. For the manufacturing of diffractive optics, green manufacturing becomes the prerequisite with timely considerations of Environmental, Social, and Governance (ESG). Conventional manufacturing processes such as semiconductor lithography or nano /micro imprinting utilize a large amount of harmful chemicals. Meanwhile, direct laser writing emerges as one of the key solution candidates, offering clear advantages over others, especially in terms of eco-friendliness due to the simple manufacturing process with less chemical usage. In this comprehensive review, we present recent advances in the analytical design, green manufacturing of electrically tunable smart light-weight planar optics, and their promising applications in space optics, photovoltaics, and optical imaging, highlighting the necessity for tunability in focal length, aberration, transparency, and beam propagation direction. Various types of electrically tunable diffractive optical elements utilizing active modulation of refractive index, geometrical shape, and bandgap have been discussed. Finally, this review concludes by proposing the integration of ultra-thin and light-weight diffractive optics presenting potential applications in micro-electronics, biomedical imaging, space exploration, and extended reality.

Detection of extragalactic magnetic massive stars

odot $ leave behind neutron stars and black holes by the end of their evolution. The merging of binary compact remnant systems produces astrophysical transients detectable by gravitational wave observatories. Studies of magnetic fields in massive stars with low metallicities are of particular interest because they provide important information on the role of magnetic fields in the star formation of the early Universe. While several detections of massive Galactic magnetic stars have been reported in the last few decades, the impact of a low-metallicity environment on the occurrence and strength of stellar magnetic fields has not yet been explored. Because of the similarity between Of?p stars in the Magellanic Clouds (MCs) and Galactic magnetic Of?p stars, which possess globally organised magnetic fields, we searched for magnetic fields in Of?p stars in the MCs. Additionally, we observed the massive contact binary Cl$*$ NGC\,346\,SSN7 in the Small Magellanic Cloud to test the theoretical scenario that the origin of magnetic fields involves a merger event or a common envelope evolution. We obtained and analysed measurements of the magnetic field in four massive Of?p stars in the MCs and the binary Cl$*$ NGC\,346\,SSN7 using the ESO/VLT FORS2 spectrograph in spectropolarimetric mode. We detected kilogauss-scale magnetic fields in two Of?p-type stars and in the contact binary Cl$*$ NGC\,346\,SSN7. These results suggest that the impact of low metallicity on the occurrence and strength of magnetic fields in massive stars is low. However, because the explored stellar sample is very small, additional observations of massive stars in the MCs are necessary.

Beam Scanning System for an Industrial Electron Accelerator

To create a compact system for scanning the beam along the conveyor, this paper considers the horizontal placement of the accelerator with a magnetic system with rotating the beam by 90◦ . A three-dimensional simulation of the magnetic system and the dynamics of electrons in it was performed. Dose distributions were also obtained in the near-surface region of the irradiated object, on the basis of which the optimal laws of change in the current and voltage of the scanning magnet were determined, which provide the required conditions for irradiating the product

Multicenter Investigation of Drug-Resistance in Burkholderia Cepacia Bloodstream Infections in Hebei Province, China, from 2016 to 2021.

To compare the epidemiological characteristics and drug resistance of Burkholderia cepacia isolated from blood cultures, and to provide data support and a scientific basis for the clinical treatment and detection of hospital infections. The Hebei Province Antimicrobial Surveillance Network received 349 B. cepacia strains isolated from blood cultures reported by 83 hospitals, from 2016 to 2021. These strains were identified by MALDI-TOF MS and, the antibiotic sensitivity tests were carried out using the VITEK 2 COMPACT system. The 2023 Institute of Clinical and Laboratory Standardization drug-susceptibility breakpoints were used for drug susceptibility testing and the data were analyzed using WHONET5.6 software. A total of 349 B. cepacia strains were isolated from 2016 to 2021, including 68 strains from secondary hospitals and 281 strains from tertiary hospitals. The ratios of male: female patients with B. cepacia bloodstream infections in all hospitals, secondary hospitals, and tertiary hospitals were 1.49:1 (209/140), 2.09:1 (46/22), and 1.38:1 (163/118), respectively. Most B. cepacia strains were isolated in intensive care units (ICUs), followed by internal medicine departments, accounting for 49.57% (173/349) and 22.92% (80/349), respectively. Regarding the age distribution, most patients were elderly (>65 years, 57.59%, 201/349), with numbers of patients gradually declining with decreasing of age. The resistance rates for levofloxacin, ceftazidime, and sulfamethoxazole decreased over the 6-year period (P<0.05), while there were no significant changes in the resistance rates for meropenem, chloramphenicol, and minocycline (P>0.05). There was no significant difference in drug-resistance rates between secondary and tertiary hospitals (P>0.05). Attention should be paid to bloodstream infections caused by B. cepacia, especially elderly patients and patients admitted to the ICU. The difficult treatment characteristics of B. cepacia bloodstream infections mean that laboratories and clinicians should pay careful attention to drug resistance to provide a basis for their prevention and empirical treatment.

A techno-economic assessment of hydrogen and methane production from the anaerobic treatment of vinasse and glycerol: single- vs. two-stage process

The best-case scenario for anaerobic digestion (AD) could include co-digestion and two-stage systems, a combination that has not yet been extensively studied. This study aimed at evaluating the effect of increasing the organic loading rate from 5 to 20 kg-COD/m3/d in second-stage thermophilic (55 °C, CH4-RThermo) and mesophilic (25 ± 5 °C, CH4-RMeso) anaerobic fluidized bed reactors (AFBR) fed with sugarcane vinasse and glycerol (1:1 on a COD basis) previously fermented in a thermophilic AFBR. AD was stable with high methane production and COD removal up to 20 kg-COD/m3/d for CH4-RThermo (4.53 L-CH4/L/d; 79%) and CH4-RMeso (3.85 L-CH4/L/d; 66%), respectively. At 20 kg-COD/m3/d, CH4-RMeso failed due to acid accumulation (1,279mg/L), which probably inhibited methanogenic activity. Results of two-stage thermophilic + thermophilic (H2-RThermo + CH4-RThermo) were compared with a thermophilic single-stage AFBR. In comparison to the two-stage system, for 10, 15, and 20 kg- COD/m3/d, the single-stage energetic yields were higher at 33, 26 and 22%, respectively. A techno-economic assessment was conducted. The scale-up and economic analyses revealed that the single-stage would be the most compact system (17,820 vs. 20,560 m3) with the lowest initial investment (USD 45M vs. USD 52M), highest net present value (NPV) (USD 58M vs. USD 47M), and internal rate of return (IRR) (18 vs. 16%) compared to the best two-stage system (thermophilic + thermophilic). A Monte Carlo simulation indicated a 12% risk of financial loss at 20 kg-COD/m3/d for the single-stage system. Furthermore, it showed that variation on the capitalization rate, inflation, and the electricity sales price can significantly affect the NPV. Therefore, in addition to better laboratory performance, the single-stage system is simpler to operate, less costly, and would be more suitable for industrial scale implementation.

Compact Off-axis Reflective Optical System Design Combining Freeform Mirror and Freeform Detector

Minimizing system size and weight without sacrificing the desired imaging performance is a crucial and challenging goal in the design of off-axis optical systems. In this paper, we propose a design concept that combines freeform mirror and freeform detector to achieve more compact off-axis optical systems. Initially, by applying nodal aberration theory, the optimal focal surface shape for off-axis systems is demonstrated to be an off-axis paraboloid or even a freeform surface, rather than the commonly assumed spherical shape. Subsequently, we show the ability of the design concept to reduce off-axis system volume through a design example of a fast and wide-field off-axis three-mirror system. Results indicate that, under the same design parameters and imaging quality, the design with a freeform detector is 80% smaller than that with a flat detector in terms of volume. Finally, the bending capability of the freeform detector presented in this paper is ensured through finite element analysis, and its surface accuracy is achievable based on the current precision level of curved detector fabrication. The proposed design concept holds promise for application in planetary science, where the imaging performance of the instrument is highly required and the size and weight are strictly limited.

Experimental characterization of discrimination capabilities of EJ-276 and EJ-276G read by SiMP by pulse-shape analysis techniques

This work aims at the investigation of the Pulse Shape Discrimination (PSD) capabilities of two very compact detection systems composed of a 3x3x3 cm3 EJ 276 and a 3x3x3 cm3 EJ 276G (the latter green shifted version) plastic scintillators, both coupled to Silicon Photomultiplier (SiPM). The studied systems are supposed to be the basic elementary cell of a new multi-detector for simultaneous detection of neutrons and light charged particles called NArCoS (Neutron Array for Correlation Studies) having both high angular and energy resolution. In this perspective, the results of the experimental qualification of two prototypes with gamma and alpha radioactive sources and in beam tests are reported, in order to characterize the optimum choice for the new device.

Laboratory demonstration of Grating Embedded Mirrors for single-shot heliostat optical metrology

Abstract Concentrated solar power (CSP) plants need to monitor the surface slope error of thousands of heliostats with sub-milliradian accuracy. Large numbers of heliostats installed in harsh environments means that measurement speed and durability are key design considerations for metrology systems. We present a compact, accurate, and high-speed heliostat slope error metrology system that is robust to the harsh environmental conditions at CSP plants. The system is composed of (1) Grating Embedded Mirrors (GEMs), which have multiple phase diffraction gratings written within a glass mirror substrate, and (2) a compact optical system, the Diffractive Auto-Stigmatic Hartmann Camera (DASHCam). Using focused ultrafast laser pulses, we write phase gratings within float glass mirror facets without damaging the reflective coating. The gratings direct a small fraction of incident light to non-specular directions, which the DASHCam senses from a virtual center of curvature to measure the facet slopes at each grating patch. In a CSP plant, each heliostat facet would be a GEM, and the DASHCam would rapidly measure slope and canting errors during heliostat manufacturing, installation, or operation. We fabricated 0.1 meter-diameter GEMs, built a prototype DASHCam system. Our results show, in a laboratory environment, 24 μrad RMS measurement repeatability and 47 μrad RMS accuracy, with single-shot image capture. The combination of GEMs and DASHCam is a promising metrology approach that could lead to improved optical accuracy of heliostats throughout their life cycle. This work serves as a proof of principle for this system.

Discovery of two warm mini-Neptunes with contrasting densities orbiting the young K3V star TOI-815

We present the discovery and characterization of two warm mini-Neptunes transiting the K3V star TOI-815 in a K–M binary system. Analysis of its spectra and rotation period reveal the star to be young, with an age of 200−200+400 Myr. TOI-8l5b has a 11.2-day period and a radius of 2.94 ± 0.05 R⊕ with transits observed by TESS, CHEOPS, ASTEP, and LCOGT. The outer planet, TOI-8l5c, has a radius of 2.62 ± 0.10 R⊕, based on observations of three nonconsecutive transits with TESS; targeted CHEOPS photometry and radial velocity follow-up with ESPRESSO were required to confirm the 35-day period. ESPRESSO confirmed the planetary nature of both planets and measured masses of 7.6 ± 1.5 M⊕ (ρP = 1.64−0.31+0.33 g cm−3) and 23.5 ± 2.4 M⊕ (ρP = 7.2−1.0+1.1 g cm−3), respectively. Thus, the planets have very different masses, which is unusual for compact multi-planet systems. Moreover, our statistical analysis of mini-Neptunes orbiting FGK stars suggests that weakly irradiated planets tend to have higher bulk densities compared to those undergoing strong irradiation. This could be ascribed to their cooler atmospheres, which are more compressed and denser. Internal structure modeling of TOI-815b suggests it likely has a H-He atmosphere that constitutes a few percent of the total planet mass, or higher if the planet is assumed to have no water. In contrast, the measured mass and radius of TOI-815c can be explained without invoking any atmosphere, challenging planetary formation theories. Finally, we infer from our measurements that the star is viewed close to pole-on, which implies a spin-orbit misalignment at the 3σ level. This emphasizes the peculiarity of the system’s orbital architecture, and probably hints at an eventful dynamical history.

Automatic measurement of water infiltration into the soil

ABSTRACT In hydrological modeling and for the development of projects related to soil and water conservation and civil engineering, determination of water infiltration variables into the soil plays a key role. However, measuring infiltration with manual infiltrometers is work-intensive and requires several people, which casts doubts on the consistency of the process description. Our objective was to develop automated and compact systems for data acquisition by double-concentric-ring and Cornell infiltrometers. The systems are based on air differential pressure sensors and microcontrollers using open-source software and a simple construction. We developed ten sets of automatic infiltrometers for each method that were properly calibrated. The equipment was validated in the field, and the alignment of the automatically measured with the hand-measured infiltration data was considered satisfactory. The proposed systems make data records of infiltration and associated variables possible, with less operator dependence than manual measurement strategies. In addition, the enhanced resolution resulting from infiltrometer automation makes the infiltration curve more representative, especially in the initial infiltration stage.

Bacteriophage Endolysins Antibacterial Effect against S. mutans Isolated from Dental Caries: An In-Vitro Study

Background: Many bacterial infections including dental caries that caused by Streptococcus mutans (S. mutans) were difficult to be treated due to the unavailability of effective antibiotics. Therefore, it requires to focus the attention on endolysin as an antibacterial agent. This study was designed to evaluate the In-vitro effectiveness of specific bacteriophage endolysins against S. mutans isolated from dental caries.Methods: Twenty-five isolates of S. mutans were collected from patients with dental caries attended to Al-Imamain Al-Kadhimain, Medical City Hospital, and AL-Ameen Health Center, during the period from December 2021 to May 2022. The S. mutans isolates were identified by culturing them on their specific mitis salivarius sucrose bacitracin tellurite media (MS-SBT agar), morphological characteristics, gram staining, biochemical tests and VITEK 2 compact system. Seven of these S. mutans isolates were used for the in-vitro study.Results: The bacteriophage endolysin enzyme extracted from the corresponding S. mutans isolate was effective as In-vitro antibacterial agent with minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) ranging between (13.63 – 17.83) µg/ml and (17.04-22.28) µg/ml respectively.Conclusion: The endolysin was effective as antibacterial agent against multi-drug resistant (MDR) S. mutans upon growing and testing on culture media.

Compact and Wearable Ventilator System for Enhanced Patient Care

Developing an innovative response to the challenges presented by the COVID-19 pandemic, our initiative strategically addresses the pressing issue of ventilator shortages and the intricacies of patient care within medical facilities. The primary focus is on the creation of a compact and wearable ventilator using embedded systems technology. Inspired by the surge in mechanical ventilator designs during the pandemic, our proposed system evolves from a simple, cost-effective device to a sophisticated solution tailored to meet the specific demands of pulmonologists and medical practitioners. The urgency in healthcare, compounded by the limited availability of ventilators, underscores the critical need for a portable and effective solution. Traditional ventilators are complicated due to challenges such as size, weight, cost, and complexity, confining their use to medical facilities and elevating the risk of secondary infections. To combatthese issues, our project seeks to design a smaller, more accessible ventilator, presenting a practical alternative for patients facing economic constraints or restricted access to medical facilities.