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Measurements of ultrafast transient processes, of temporal durations in the picosecond and femtosecond regime, are made possible by femtosecond pump probe transient absorption spectroscopy. Such an ultrafast pump probe transient absorption setup has been implemented at the CSIR National Laser Centre and has been applied to investigate energy transfer processes in different parts of photosynthetic systems. In this paper we report on our first results obtained with Malachite green as a benchmark. Malachite green was chosen because the lifetime of its excited state is well known. We also present experimental results of the ultrafast energy transfer of light-harvesting complexes in samples prepared from spinach leaves. Various pump wavelengths in the range 600-680 nm were used; the probe was a white light continuum spanning 420-700 nm. The experimental setup is described in detail in this paper. Results obtained with these samples are consistent with those expected and achieved by other researchers in this field. [ABSTRACT FROM AUTHOR]

SARS-CoV-2 is a threat to public health due to its ability to undergo crucial mutations, increasing its infectivity and decreasing the vaccine's effectiveness. There is a need to find and introduce alternative and effective methods of controlling SARS-CoV-2. LLLT treats diseases by exposing cells or tissues to low levels of red and near-infrared light. The study aims to investigate for the first time the impact of LLLT on SARS-CoV-2 infected HEK293/ACE2 cells and compare them to uninfected ones. Cells were irradiated at 640 nm, at different fluences. Subsequently, the effects of laser irradiation on the virus and cells were assessed using biological assays. Irradiated uninfected cells showed no changes in cell viability and cytotoxicity, while there were changes in irradiated infected cells. Furthermore, uninfected irradiated cells showed no luciferase activity while laser irradiation reduced luciferase activity in infected cells. Under SEM, there was a clear difference between the infected and uninfected cells., (© 2023 Council for Scientific and Industrial Research. Journal of Biophotonics published by Wiley‐VCH GmbH.)

Tuberculosis (TB), a bacterial infection caused by Mycobacterium tuberculosis, is highly contagious and can lead to severe health complications if left untreated. This review article discusses the importance of early detection and treatment and its global incidence and epidemiology, emphasizing its impact on vulnerable populations and its role as a major cause of death worldwide. Furthermore, it highlights the challenges faced with diagnosing TB. To overcome these challenges, point-of-care devices have emerged as promising tools for rapid and accurate TB detection. These include devices such as nucleic acid amplification tests (NAATs), lateral flow assays (LFAs), and microfluidic-based assays, which offer advantages such as rapid results, portability, and the ability to detect drug-resistant strains. Optical-based devices, such as photonic micro-ring sensors, silicon platform-based sensors, plasmonic-based platforms, microfluidics, and smartphone imaging, are some of the highlighted optical-based devices with the potential to detect TB. These devices can detect TB in sputum samples with high sensitivity and specificity. Optical-based diagnostic devices have the potential to offer the advantages of detecting low concentrations of target molecules and being adaptable to detect multiple targets simultaneously. Using these devices in a clinical setting makes them suitable for their application in improving access to diagnostic testing that enables earlier detection and treatment of TB. Furthermore, these devices would improve TB's global health issue, which requires comprehensive research, prevention, and treatment efforts., Competing Interests: Declaration of Competing Interest The authors declare no conflict of interest., (Copyright © 2023. Published by Elsevier B.V.)

Despite major efforts made to control tuberculosis disease (TB), this disease continues to present a major global health challenge and drug resistance is continuously growing. TB is caused by Mycobacterium tuberculosis and spreads exclusively via human-to-human contact transmission. Therefore, early detection and diagnosis for proper treatment with active TB have a great impact on public health. Regardless, most people in developing countries with TB or TB-associated symptoms do not have access to an adequate initial diagnosis. Available bacteriologic-based techniques are either inefficient or may require a longer turnaround time from the laboratory. Contemporarily, non-bacteriologic based methods have both questionable sensitivity and specificity and while others cannot distinguish between active and latent TB. Thus, additional efforts have been made to find accurate diagnostic tests for TB. Herein, we review the available methods used for TB diagnosis, and in addition, we explore point of care (POC) diagnostics as an alternative way to develop TB diagnostic tests and further evaluate whether bioinformatics can be used as an additional screening tool for identification of possible TB biomarkers for the development of POC TB diagnostics, which is part of our research focus., Competing Interests: Conflicts of interest The authors have none to declare., (Copyright © 2023 Tuberculosis Association of India. Published by Elsevier B.V. All rights reserved.)

The use of femtosecond laser to create sub-microscopic transient pores on the cell membrane allowing exogenous material into mammalian cells has become a very efficient optical delivery method over the past decade. This study focuses on laser-enabled delivery of antiretroviral (ARV) drugs into HIV-1 infected TZM-bl cells in vitro. A 1 kHz femtosecond laser emitting at a wavelength of 800 nm was used to photoporate cells at 6.5 μW. Trypan blue was used for characterisation and its uptake was quantified using Matlab software. Cell membrane damage was assessed using the lactate dehydrogenase (LDH) assay while HIV-1 infection was assessed using luciferase assay. Our results showed successful delivery of ARVs into HIV-1 infected cells without compromising their cell membranes, subsequently reducing the level of infection. The LDH assay showed no significant cell membrane damage of laser-treated cells, and the luciferase assay demonstrated significant reduction in the level of HIV-1 infection., (© 2022 The Authors. Journal of Biophotonics published by Wiley-VCH GmbH.)

The increase in demand for pharmaceutical treatments due to pandemic-related illnesses has created a need for improved quality control in drug manufacturing. Understanding the physical, biological, and chemical properties of APIs is an important area of health-related research. As such, research into enhanced chemical sensing and analysis of pharmaceutical ingredients (APIs) for drug development, delivery and monitoring has become immensely popular in the nanotechnology space. Nanomaterial-based chemical sensors have been used to detect and analyze APIs related to the treatment of various illnesses pre and post administration. Furthermore, electrical and optical techniques are often coupled with nano-chemical sensors to produce data for various applications which relate to the efficiencies of the APIs. In this review, we focus on the latest nanotechnology applied to probing the chemical and biochemical properties of pharmaceutical drugs, placing specific interest on several types of nanomaterial-based chemical sensors, their characteristics, detection methods, and applications. This study offers insight into the progress in drug development and monitoring research for designing improved quality control methods for pharmaceutical and health-related research.

In this study, we show how surface enhanced Raman spectroscopy (SERS) can be used to monitor the molecular behaviour of aspirin and tenofovir as a means of screening medication for quality control purposes. Gold-coated slides combined with gold/dextran nanoaggregates were used to provide signal enhancement of the drugs using SERS. Aspirin (10% w / v ) and tenofovir (20% v / v ) were analysed in the presence of the nanomaterials to determine trends in molecular response to changes in gold/dextran concentrations. Qualitative analysis of the functional groups showed specific trends where the peak area increased with polarizability, electron density and decreased atomic radii. Steric hinderance effects also affected the trends in peak area due to the amount of gold/dextran nanoparticles in solution. Statistical analysis provided accurate and precise linear relationships (R 2 = 0.99) for the ester and adenine functional groups of aspirin and tenofovir, respectively. From the above findings, the combined use of gold nano-scaffolds and gold/dextran nanomaterials amplified the Raman signal from the drugs to allow for systematic evaluation of their molecular properties. Although more experiments to correlate the findings are still needed, this SERS approach shows great potential as a screening method in the quality control of medications.

Background: Human immunodeficiency virus (HIV) infection remains a global health challenge despite the use of antiretroviral therapy, which has led to a significant decline in the mortality rates. Owing to the unavailability of an effective treatment to completely eradicate the virus, researchers continue to explore new methods. Low level laser therapy (LLLT) has been widely used to treat different medical conditions and involves the exposure of cells or tissues to low levels of red and near infrared light. The study aimed to determine the effect of combining two unrelated therapies on HIV infection in TZM-bl cells., Methods: In the current study, LLLT was combined with efavirenz, an HIV reverse transcriptase inhibitor to establish their impact on HIV infection in TZM-bl cells. Both the HIV infected and uninfected cells were laser irradiated using a wavelength of 640 nm with fluencies of 2-10 J/cm 2 ., Results: The impact of HIV, efavirenz and irradiation were determined 24 h post irradiation using biological assays. Luciferase assay results showed that the combination of LLLT and efavirenz significantly reduced HIV infection in cells, despite the undesirable effects observed in the cells as demonstrated by cell morphology, proliferation and cell integrity assay. Flow cytometry results demonstrated that cell death was mainly through necrosis while fluorescence microscopy showed the production of reactive oxygen species in HIV infected cells., Conclusion: Efavirenz and LLLT significantly reduced HIV infection in TZM-bl cells. Furthermore, the death of HIV infected cells was due to necrosis., Competing Interests: Conflicts of Interest The authors declare no conflicts of interest., (Copyright © 2020 Chang Gung University. Published by Elsevier B.V. All rights reserved.)

Viral infections pose significant health challenges globally by affecting millions of people worldwide and consequently resulting in a negative impact on both socioeconomic development and health. Corona virus disease 2019 (COVID-19) is a clear example of how a virus can have a global impact in the society and has demonstrated the limitations of detection and diagnostic capabilities globally. Another virus which has posed serious threats to world health is the human immunodeficiency virus (HIV) which is a lentivirus of the retroviridae family responsible for causing acquired immunodeficiency syndrome (AIDS). Even though there has been a significant progress in the HIV biosensing over the past years, there is still a great need for the development of point of care (POC) biosensors that are affordable, robust, portable, easy to use and sensitive enough to provide accurate results to enable clinical decision making. The aim of this study was to present a proof of concept for detecting HIV-1 pseudoviruses by using anti-HIV1 gp41 antibodies as capturing antibodies. In our study, glass substrates were treated with a uniform layer of silane in order to immobilize HIV gp41 antibodies on their surfaces. Thereafter, the HIV pseudovirus was added to the treated substrates followed by addition of anti-HIV gp41 antibodies conjugated to selenium nanoparticle (SeNPs) and gold nanoclusters (AuNCs). The conjugation of SeNPs and AuNCs to anti-HIV gp41 antibodies was characterized using UV-vis spectroscopy, transmission electron microscopy (TEM) and zeta potential while the surface morphology was characterized by fluorescence microscopy, atomic force microscopy (AFM) and Raman spectroscopy. The UV-vis and zeta potential results showed that there was successful conjugation of SeNPs and AuNCs to anti-HIV gp41 antibodies and fluorescence microscopy showed that antibodies immobilized on glass substrates were able to capture intact HIV pseudoviruses. Furthermore, AFM also confirmed the capturing HIV pseudoviruses and we were able to differentiate between substrates with and without the HIV pseudoviruses. Raman spectroscopy confirmed the presence of biomolecules related to HIV and therefore this system has potential in HIV biosensing applications., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2020 Published by Elsevier B.V. on behalf of King Saud University.)

Cancer is among the leading causes of mortality and morbidity worldwide. Among the different types of cancers, lung cancer is considered to be the leading cause of death related to cancer and the most commonly diagnosed form of such disease. Chemotherapy remains a dominant treatment modality for many types of cancers at different stages. However, in many cases, cancer cells develop drug resistance and become nonresponsive to chemotherapy, thus, necessitating the exploration of alternative and /or complementary treatment modalities. Photodynamic Therapy (PDT) has emerged as an effective treatment modality for various malignant neoplasia and tumors. In PDT, the photochemical interaction of light, Photosensitizer (PS) and molecular oxygen produces Reactive Oxygen Species (ROS), which induces cell death. Combination therapy, by using PDT and chemotherapy, can promote synergistic effect against this fatal disease with the elimination of drug resistance, and enhancement of the efficacy of cancer eradication. In this review, we give an overview of chemotherapeutic modalities, PDT, and the different types of drugs associated with each therapy. Furthermore, we also explored the combined use of chemotherapy and PDT in the course of lung cancer treatment and how this approach could be the last resort for thousands of patients that have been diagnosed by this fatal disease., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

The introduction of highly active antiretroviral therapy (HAART) has significantly increased life expectancy and improved management of the human immunodeficiency virus-1 (HIV-1) disease globally. This well-established treatment regime has shown to reduce viral capacity to undetectable limits when using traditional clinical assays. The establishment of viral reservoirs during the early stages of infection are the major contributors to failure of the current regimens to eradicate HIV-1 infection since the reservoirs are not affected by antiretroviral drugs (ARVs). Therefore, advanced modification of the present treatment and investigation of novel antiretroviral drug delivery system are needed. The aim of this study was to use femtosecond (fs) laser pulses to deliver ARVs into HIV-1 infected TZMbl cells. Different ARVs were translocated into TZMbl cells using fs pulsed laser (800 nm) with optimum power of 4 μW and 10 ms laser to cell exposure time. Changes in cellular processes were evaluated using cellular morphology, viability, cytotoxicity and luciferase activity assays. Cells treated with the laser in the presence of ARVs showed a significant reduction in viral infectivity, cell viability and an increase in cytotoxicity. This study demonstrated that fs laser pulses were highly effective in delivering ARVs into HIV-1 infected TZMbl cells, causing a significant reduction in HIV-1 infection., (© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Transmission measurement has been perceived as a potential candidate for label-free investigation of biological material. It is a real-time, label-free and non-invasive optical detection technique that has found wide applications in pharmaceutical industry as well as the biological and medical fields. Combining transmission measurement with optical trapping has emerged as a powerful tool allowing stable sample trapping, while also facilitating transmittance data analysis. In this study, a near-infrared laser beam emitting at a wavelength of 1064 nm was used for both optical trapping and transmission measurement investigation of human immunodeficiency virus 1 (HIV-1) infected and uninfected TZM-bl cells. The measurements of the transmittance intensity of individual cells in solution were carried out using a home built optical trapping system combined with laser transmission setup using a single beam gradient trap. Transmittance spectral intensity patterns revealed significant differences between the HIV-1 infected and uninfected cells. This result suggests that the transmittance data analysis technique used in this study has the potential to differentiate between infected and uninfected TZM-bl cells without the use of labels. The results obtained in this study could pave a way into developing an HIV-1 label-free diagnostic tool with possible applications at the point of care ., (© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Human immunodeficiency virus (HIV-1) infection remains a major health problem despite the use of highly active antiretroviral therapy (HAART), which has greatly reduced mortality rates. Due to the unavailability of an effective vaccine and treatment that would completely eradicate the virus in infected individuals, the quest for new therapies continues. Low level laser therapy (LLLT) involves the exposure of cells to low levels of red or infrared light. LLLT has been widely used in different medical conditions, but not in HIV-1 infection. This study aimed to determine the effects of LLLT on HIV-1 infected and uninfected TZM-bl cells. Both infected and uninfected cells were irradiated at a wavelength of 660 nm with different fluences from 2 J/cm 2 to 10 J/cm 2 . Changes in cellular responses were assessed using cell morphology, viability, proliferation, cytotoxicity and luciferase activity assays. Upon data analysis, uninfected irradiated cells showed no changes in cell morphology, viability, proliferation and cytotoxicity, while the infected irradiated cells did. In addition, laser irradiation reduced luciferase activity in infected cells. Finally, laser irradiation had no inhibitory effect in uninfected cells, whereas it induced cell damage in a dose dependent manner in infected cells., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The application of UV lidar to measure isoprene concentrations for environmental studies has been investigated. With a hard target lidar system at 223 nm, isoprene mixing ratios above eucalyptus trees were measured with a sensitivity of about 1 ppbv. Results over a long timescale were compared with an existing model of isoprene emission for a wide range of temperature and sunlight values. Fast time dependent results yielded a leaf emission rate of 25 microg g(-1) hour(-1), consistent with emission from other eucalyptus species. Requirements for development of the system for range resolved isoprene number density measurements using atmospheric backscatter lidar are discussed.