Intracameral Antibiotics as Prophylaxis in Cataract Surgery; a Mini-Review of Literature

Purpose: To conduct a mini-review of intracameral antibiotics usage as prophylaxis for post cataract surgery endophthalmitis.Materials and Methods: We conducted a brief search of English literature regarding the recent developments in use of various intracameral antibiotics as anaphylaxis for post cataract surgery endophthalmitis.Results: The effect of prophylactic intracameral antibiotics in reducing post cataract surgery endophthalmitis is still a controversial subject.  Randomized clinical trials (RCTs) are great sources to confirm benefits from prophylactic intracameral antibiotics. Several recent surveys have reported higher rates of endophthalmitis among cataract patients not receiving prophylactic intracameral antibiotics compared with those receiving antibiotics.Conclusion: Based on the latest findings it seems that more surgeons should set aside their doubts and use intracameral antibiotics as routine prophylaxis to reduce the rate of post cataract surgery endophthalmitis

Spectroscopic Study of Localized States in Twisted Semiconducting Heterostructures and Charge Transfer Driven Phenomena in a-RuCl₃ Heterointerfaces

This thesis investigates the unique properties of 2D devices such as twisted semiconducting bilayers and a-RuCl₃ heterostructures employing scanning tunneling microscopy (STM) and spectroscopy (STS) probes. The research presented here sheds light on the vast opportunities that 2D materials provide in condensed matter systems as well as future device applications. Among 2D materials, transition metal dichalcogenide (TMD) heterobilayers provide a promising platform to study many quantum phenomena such as excitonic states due to their tunability of band gap. In addition, TMDs are excellent candidates to achieve localized states and carrier confinement, crucial for single photon emitters used in quantum computation and information. We begin this thesis with a brief overview of STM/STS and utilizing these techniques on 2D materials in the first and second chapters.The third chapter of this work investigates the twisted bilayer of WSe₂ and MoSe₂ in the H-stacking configuration using STM/STS which was previously challenging to measure. The spectroscopic results obtained from the heterobilayer indicate that a combination of structural rippling and electronic coupling generates unexpectedly large \moire potentials, in the range of several hundred meV. Our analysis reveals that the \moire structure and internal strain, rather than interlayer coupling, are the main factors of the moire potential. Large moire potentials lead to deeply trapped carriers such as electron-hole pairs, so-called excitons. Our findings open new routes toward investigating excitonic states in twisted TMDs. In the next chapter, we investigate the ultralocalized states of twisted WSe₂/MoSe₂ nanobubbles. Mechanical and electrical nanostructurings are expected to modify the band properties of transition metal dichalcogenides at the nanoscale. To visualize this effect, we use STM and near-field photoluminescence to examine the electronic and optical properties of nanobubbles in the semiconducting heterostructures. Our findings reveal a significant change in the local bandgap at the nanobubble, with a continuous evolution towards the edge of the bubble. Moreover, at the edge of the nanobubble, we show the formation of in gap bound states. A continuous redshift of the interlayer exciton on entering the bubble is also detected by the nano-PL. Using self-consistent Schrodinger-Poisson simulations, we further show that strong doping in the bubble region leading to band bending is responsible for achieving ultralocalized states. Overall, this work demonstrates the potential of 2D TMDs for developing well-controlled optical emitters for quantum technologies and photonics. We next turn to the effect of the electric field in band gap tuning of WSe₂/WS₂ heterobilayer. The tunability of band gap is a crucial element in device engineering to achieve quantum emitters. The electrostatic gate generates doping and an electric field giving access to continuous tunability, higher doping level, and integration capability to nanoelectronic devices. We employ scanning tunneling microscopy (STM) and spectroscopy (STS) to probe the band properties of twisted heterobilayer with high energy and spatial resolution. We observe continuous band gap tuning up to several hundreds of meV change by sweeping the back gate. We introduced a capacitance model to take into account the finite tip size leading to an enhanced electric field. The result of our calculation captures well the band gap change observed by STS measurements. Our study offers a new route toward creating highly tunable semiconductors for carrier confinement in quantum technology. In the next chapters, we focus on a-RuCl₃ heterointerfaces. We first explore the nanobubble of graphene/a-RuCl3 to create sharp p-n junctions. The ability to create sharp lateral p-n junctions is a critical requirement for the observation of numerous quantum phenomena. To accomplish this, we used a charge-transfer based heterostructure consisting of graphene and a-RuCl₃ to create nanoscale lateral p-n junctions in the vicinity of nanobubbles. Our approach relied on a combination of scanning tunneling microscopy (STM) and spectroscopy (STS), as well as scattering-type scanning near-field optical microscopy (s-SNOM), which allowed us to examine both the electronic and optical responses of these nanobubble p-n junctions. Our results showed a massive doping variation across the nanobubble with a band offset of 0.6 eV. Further, we observe the formation of an abrupt junction along nanobubble boundaries with an exceptionally sharp lateral width (<3 nm). This is one order of magnitude smaller length scale than previous lithographic methods. Our work paves the way toward device engineering via interfacial charge transfer in graphene and other low-density 2D materials. In chapter 7, we describe the use of low-temperature scanning tunneling microscopy (STM) measurements to observe the \moire pattern in graphene/a-RuCl3 heterostructure to validate the InterMatch method. This method is effective in predicting the charge transfer, strain, and stability of an interface. The InterMatch method was applied to moire patterns of graphene/a-RuCl3 to predict the stable interface structure. STM topographs show three regions with distinct moire wavelengths due to atomic reconstructions. Using the InterMatch method, we perform a comprehensive mapping of the space of superlattice configurations and we identify the energetically favorable superlattices that occur in a small range of twist angles. This range is consistent with the STM results. Moreover, the spectra on these regions exhibit strong resonances with the spacing between resonances following the expectation from Landau levels on a Dirac spectrum due to strain and doping. The results of our scanning tunneling microscopy (STM) measurements confirm that the InterMatch method is effective in predicting the charge transfer and stability of interfaces between materials. We next investigate WSe₂/a-RuCl₃ heterostructure through a multi-faceted approach. Our exploration encompassed diverse techniques such as STM, and optical measurements. We detect a significant charge transfer between the two layers by STM measurements, leading to a shift in the Fermi level towards the valence band of WSe₂. Our findings are supported by optical measurements and DFT calculations, which confirm the p-doped WSe₂ observed through STM. The results of this work highlight a-RuCl₃ potential for contact engineering of TMDs and unlocking their functionalities for the next generation optoelectronic devices. In the last chapter of this thesis, I provide a brief conclusion as well as a few future directions and insights for investigating 2D materials

Daclatasvir/Sofosbuvir versus Ledipasvir/Sofosbuvir in Patients with Hepatitis C Virus Infection Genotypes 1 and 3

Background: The new direct-acting antiviral agents (DAAs) with high efficacy, low resistance, and low rate of adverse events (AEs) have shown promising outcomes for hepatitis C virus (HCV) treatment. This study assessed the efficacy and safety of Daclatasvir/Sofosbuvir (DCV/SOF) compared to Ledipasvir/Sofosbuvir (LDV/SOF) in patients with HCV infection in the real-world setting in Iran. Materials and Methods: A total of 42 patients with HCV infection were treated with either LDV/SOF (genotype 1) or DCV/SOF (genotypes 1, 3 or unknown) with or without ribavirin (RBV). Assessment of risk factors, laboratory tests, sustained virologic response at post-treatment week 12 (SVR12), and AEs were performed. Results: The highest risk factor for HCV transmission was major surgery (50.0%), followed by tattooing (40.5%), phlebotomy (40.5%), and dental surgery (40.5%). No statistically significant relationships between genotypes and risk factors were observed. In both treatment groups (LDV/SOF and DCV/SOF), all of the patients (100%) with or without cirrhosis and treatment-experience achieved SVR12. One patient with a history of failed LDV/SOF therapy achieved SVR12 following retreatment with DCV/SOF. Both treatment regimens were well-tolerated. No serious AEs or discontinuation due to AEs was observed. The most common AE across both treatment groups were fatigue (42.9%), followed by anxiety (28.6%). Numerically, more adverse events were found with the LDV/SOF regimen than with the DCV/SOF regimen. Conclusion: Our study showed an excellent safety and efficacy of DCV/SOF and LDV/SOF in Iranian patients infected with HCV. The incidence of AEs among patients treated with LDV/SOF was higher than those receiving SOF/DCV

An Improved model for OKP product planning stage in a cloud-based design environment

Nowadays, in the software world, cloud computing has great importance. This massive network has reduced the cost of software for users, but has risen in revenue from manufacturers, the products of the one-of-a-kind (OKP) companies are cloud-based, and customers access the software through the cloud, In this architecture, the company places part of the software that is expensive and does not have the ability to buy for the cloud on cloud servers, and users can connect with the cloud to the cloud using this software, But since the number of users is greater than the number of servers, they must run a scheduling mechanism to execute requests, We present a timing system for OKP products in this paper, compared with two other methods, the simulation results show the superiority of the proposed method

Seroprevalence of Hepatitis a in Hemodialysis Patient Candidate for Kidney Transplant Younger Than Forty Years

Background: Hepatitis A is a common infection during childhood, especially in developing countries. It can cause severe complications in immunocompromised patients. Due to the increasing number of kidney transplants in the country and epidemiologic shift of HAV which was observed in previous studies, we're going to evaluate the seroprevalence of hepatitis A in hemodialysis patients less than forty years serving kidney transplant candidates to follow vaccination policy for them.Materials and Methods: In a cross sectional study during 2014-2015 hepatitis A antibody levels in hemodialysis patients less than forty years in kidney transplant candidates examined in 12 hospitals in Tehran, Iran. Their serums were tested for anti HAV IgM and IgG by ELISA kits.Results: Hepatitis A virus antibody was positive in 66 (72.5%) of 91 patients. The prevalence of HAV was 0% at the range of younger than 20 and 45% in under 25 years age group. This significantly increased prevalence by increasing the age, and there was according to epidemiological shifts which were shown in other studies.Conclusion: Due to the availability of vaccine and hepatitis severe complications in immunocompromised individuals, as well as a low prevalence of positive serology in individuals under 25 years, it seems the check of antibodies in patients undergoing kidney transplantation and vaccination in seronegative persons is a logical

Machine Learning for Optical Scanning Probe Nanoscopy

The ability to perform nanometer-scale optical imaging and spectroscopy is key to deciphering the low-energy effects in quantum materials, as well as vibrational fingerprints in planetary and extraterrestrial particles, catalytic substances, and aqueous biological samples. The scattering-type scanning near-field optical microscopy (s-SNOM) technique has recently spread to many research fields and enabled notable discoveries. In this brief perspective, we show that the s-SNOM, together with scanning probe research in general, can benefit in many ways from artificial intelligence (AI) and machine learning (ML) algorithms. We show that, with the help of AI- and ML-enhanced data acquisition and analysis, scanning probe optical nanoscopy is poised to become more efficient, accurate, and intelligent

Hidden low-temperature magnetic order revealed through magnetotransport in monolayer CrSBr

Magnetic semiconductors are a powerful platform for understanding, utilizing and tuning the interplay between magnetic order and electronic transport. Compared to bulk crystals, two-dimensional magnetic semiconductors have greater tunability, as illustrated by the gate modulation of magnetism in exfoliated CrI$_3$ and Cr$_2$Ge$_2$Te$_6$, but their electrically insulating properties limit their utility in devices. Here we report the simultaneous electrostatic and magnetic control of electronic transport in atomically-thin CrSBr, an A-type antiferromagnetic semiconductor. Through magnetotransport measurements, we find that spin-flip scattering from the interlayer antiferromagnetic configuration of multilayer flakes results in giant negative magnetoresistance. Conversely, magnetoresistance of the ferromagnetic monolayer CrSBr vanishes below the Curie temperature. A second transition ascribed to the ferromagnetic ordering of magnetic defects manifests in a large positive magnetoresistance in the monolayer and a sudden increase of the bulk magnetic susceptibility. We demonstrate this magnetoresistance is tunable with an electrostatic gate, revealing that the ferromagnetic coupling of defects is carrier mediated

Nanometer-Scale Lateral p–n Junctions in Graphene/α-RuCl3 Heterostructures

[EN] The ability to create nanometer-scale lateral p-n junctions is essential for the next generation of two-dimensional (2D) devices. Using the charge-transfer heterostructure graphene/alpha-RuCl3, we realize nanoscale lateral p-n junctions in the vicinity of graphene nanobubbles. Our multipronged experimental approach incorporates scanning tunneling microscopy (STM) and spectroscopy (STS) and scattering-type scanning near-field optical microscopy (s-SNOM) to simultaneously probe the electronic and optical responses of nanobubble p-n junctions. Our STM/STS results reveal that p-n junctions with a band offset of 0.6 eV can be achieved with widths of 3 nm, giving rise to electric fields of order 108 V/m. Concurrent s-SNOM measurements validate a point-scatterer formalism for modeling the interaction of surface plasmon polaritons (SPPs) with nanobubbles. Ab initio density functional theory (DFT) calculations corroborate our experimental data and reveal the dependence of charge transfer on layer separation. Our study provides experimental and conceptual foundations for generating p-n nanojunctions in 2D materials.Research at Columbia University was supported as part of the Energy Frontier Research Center on Programmable Quantum Materials funded by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences (BES), under Award No DE-SC0019443. Plasmonic nano-imaging at Columbia University was supported by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences (BES), under Award No DE-SC0018426. J.Z. and A.R. were supported by the European Research Council (ERC-2015-AdG694097), the Cluster of Excellence “Advanced Imaging of Matter” (AIM) EXC 2056-390715994, funding by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under RTG 2247, Grupos Consolidados (IT1249-19), and SFB925 “Light induced dynamics and control of correlated quantum systems”. J.Z. and A.R. would like to acknowledge Nicolas Tancogne-Dejean and Lede Xian for fruitful discussions and also acknowledge support by the Max Planck Institute-New York City Center for Non-Equilibrium Quantum Phenomena. The Flatiron Institute is a division of the Simons Foundation. J.Z. acknowledges funding received from the European Union Horizon 2020 research and innovation programme under Marie Skłodowska-Curie Grant Agreement 886291 (PeSD-NeSL). STM support was provided by the National Science Foundation via Grant DMR-2004691. C.R.-V. acknowledges funding from the European Union Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie Grant Agreement 844271. D.G.M. acknowledges support from the Gordon and Betty Moore Foundation’s EPiQS Initiative, Grant GBMF9069. J.Q.Y. was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division. S.E.N. acknowledges support from the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Division of Scientific User Facilities. Work at University of Tennessee was supported by NSF Grant 180896

Charge Density Wave Order and Electronic Phase Transitions in a Dilute d‐Band Semiconductor

As one of the most fundamental physical phenomena, charge density wave (CDW) order predominantly occurs in metallic systems such as quasi-1D metals, doped cuprates, and transition metal dichalcogenides, where it is well understood in terms of Fermi surface nesting and electron-phonon coupling mechanisms. On the other hand, CDW phenomena in semiconducting systems, particularly at the low carrier concentration limit, are less common and feature intricate characteristics, which often necessitate the exploration of novel mechanisms, such as electron-hole coupling or Mott physics, to explain. In this study, an approach combining electrical transport, synchrotron X-ray diffraction, and density-functional theory calculations is used to investigate CDW order and a series of hysteretic phase transitions in a dilute d-band semiconductor, BaTiS3 . These experimental and theoretical findings suggest that the observed CDW order and phase transitions in BaTiS3 may be attributed to both electron-phonon coupling and non-negligible electron-electron interactions in the system. This work highlights BaTiS3 as a unique platform to explore CDW physics and novel electronic phases in the dilute filling limit and opens new opportunities for developing novel electronic devices