A critical review on quantum dots

A critical review on quantum dots: From synthesis toward applications in electrochemical biosensors for determination of disease-related biomolecules

Nanoscience or nanotechnology is a very fast-growing field of science, which has introduced various new transforming technology in the present era. One such technology is fluorescent quantum dots (QDs), which have been a part of nanotechnology since the very beginning of the field. Fluorescent quantum dots are very small nanocrystals, defines by a diameter of about 2-10 nanometers i.e. around 10-50 atoms. The most unique property of quantum dots is the resultant fluorescence of distinctive colors produced, which is highly dependent on the size of the nanocrystal.

Quantum dots are known to be consisting of a variety of structural, photochemical, and electrochemical properties also, which can be exploited to use them as a very promising technology in the field of sensing applications. The use of quantum dots as a nanomaterial in these sensing applications can increase the performance of biosensors in the market, specifically in terms of overcoming the existing issues such as detection limit, selectivity, and sensor sensitivity. The applications of quantum dots is not only limited to this, instead, it also expands to their high-level functionalization with bioreceptors. In this review article, the authors highlight how fluorescent quantum dots function and their core knowledge along with a detailed explanation of their applications in sensors to receptors.

The potential of quantum dots is immense, one of the reason is their enhanced capability to associate nanotechnology and biotechnology together. They indeed possess a huge potential to set a new paradigm in the research field to give a comprehensive view of zero-dimensional nanoparticles. These nanoparticles can be effectively used in the designing of electrochemical sensors which can be used in the diagnosis of diseases. This can specifically include identifying biomolecules such as tumor markers, depression markers, inflammatory markers, and more. Considering the huge application of quantum dots, the researcher highlights more in-depth research in the field. Detailed insight about quantum dots can help in understanding their electronic and magnetic properties in more detail. One can understand how they can be synthesized in labs efficiently for further large scale production to be used effectively at the industrial scale for biomolecule diagnosis and other related applications.

Risk Factors and Biomarkers of Ischemic Stroke in Cancer Patients

Risk Factors and Biomarkers of Ischemic Stroke in Cancer Patients

Numerous types of cancer are associated with ischemic stroke and are popularly known to be co-morbid conditions. They are two of the most frequent causes of death among the elderly population. A previous report of autopsies on cancer patients indicated that around 7.4% of the population suffered from stroke symptoms. With further analysis it was noticed that about 3.5% of the cancer patients were paralysed from strokes. 

The causes of ischemic stroke in cancer and non-cancer patients are highly different. Reports suggest, most of the cancer patients suffer from stroke mainly due to hypercoagulation. The blood clot formed restricts the blood flow to the brain, causing the cells in the brain to perish. This in turn paralyses the parts of the body controlled by the dead cells. While on the other hand, some reports suggest that stroke and cancer pathogenesis may be due to coagulopathy and atherosclerosis. The aim of this study is to study ischemic stroke in cancer patients using relevant biomarkers and compare it with non cancer patients with stroke. 

The study involved cancer patients with ischemic stroke from General Hospital in Busan, Korea. All the patients had active cancer with an onset of stroke symptoms. The control group used were patients from the same hospital, non cancer patients suffering from ischemic stroke. For examining the biomarkers, patients’ blood was collected and serum was assessed. 

The study found that biomarkers such as D-dimer levels, erythrocyte sedimentation rate (ESR), fibrinogen and Brain natriuretic peptide (BNP) were significantly higher in the cancer patients when compared to non cancer patients with stroke. 

D-dimer are one of the basic bio-markers for stroke due to their discovery as by-products of fibrinolysis. As a fibrin degradation product, dimer is directly associated with coagulation and plays a major role in hypercoagulation. Compared to non cancer ischemic stroke patients, D-dimer levels were found to be higher in cancer patients diagnosed with stroke. 

Blood coagulation in cancer patients is activated by inflammation. In this study, the authors used ESR, because of its well known use as a marker for infection and inflammation. An increased level of ESR indicating fibrinolysis was noticed in cancer stroke patients when compared to the control group.

From previous papers, it is well known that fibrinogen plays a major role in inflammation and platelet aggregation. An increase in fibrinogen is directly associated with increased risk of stroke in patients. In the current study cancer patients with ischemic stroke had a significant increase in fibrinogen than non cancer patients. 

Cancer patients with ischemic stroke portrayed high levels of stroke biomarkers when compared to the non cancer patients with ischemic stroke- control group. The above results showcase a strong relationship between the cancer patients and conditions like hypercoagulation and inflammation, which could possibly explain the frequency of paralysis in aged cancer patients leading to death. Therefore, in order to reduce any incidence of ischemic stroke in cancer patients, doctors should focus on reducing inflammation and platelet coagulation. 

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An in situ-Synthesized Gene Chip for the Detection of Food-Borne Pathogens on Fresh-Cut Cantaloupe and Lettuce

Food-borne pathogens are one of the major reasons behind endangering the life and safety of people across the globe. Fresh foods are specifically more vulnerable to these pathogens, making it crucial to have a very efficient food safety surveillance technology. The development of such technology will help in offering rapid detection of food-borne pathogens. In the present study, researchers developed an In-situ synthesized gene chip for the detection of the food-borne pathogen. Here the researchers first identified and screened the target genes by comparing the sequences of common food-borne pathogens like Salmonella, Vibrio parahemolyticus, Staphylococcus Aureus, Listeria monocytogenes and E.coli 0157:H7 from the NCBI database. Unique tilling array probes were designed that helps to target the selected genes in an optimized hybridization system. The resultant assay showed high specificity along with strong amplification signals. The results were highly accurate with a detection limit of approximately 3 log cfu/g without culturing. The detection time for the five target food-borne pathogens on the fresh-cut cantaloupe and lettuces was found to be 24 hours. This highlights the great efficacy of the detection system to rapidly monitor the pathogens on the fresh food items. Such a system can be easily incorporated as an efficient food surveillance system for checking the logistical distribution chain, the food at the processing stage, cleaning condition at the food manufacturing plants, transport, sales and more. The technology is considered valuable as it supports the safety of fresh agricultural products, reducing the overall wastage of food due to infectious pathogens.

An in situ-Synthesized Gene Chip for the Detection of Food-Borne Pathogens on Fresh-Cut Cantaloupe and Lettuce

Food-borne pathogens are one of the major reasons behind endangering the life and safety of people across the globe. Fresh foods are specifically more vulnerable to these pathogens, making it crucial to have a very efficient food safety surveillance technology. The development of such technology will help in offering rapid detection of food-borne pathogens. In the present study, researchers developed an In-situ synthesized gene chip for the detection of the food-borne pathogen. Here the researchers first identified and screened the target genes by comparing the sequences of common food-borne pathogens like Salmonella, Vibrio parahemolyticus, Staphylococcus Aureus, Listeria monocytogenes and E.coli 0157:H7 from the NCBI database. Unique tilling array probes were designed that helps to target the selected genes in an optimized hybridization system. The resultant assay showed high specificity along with strong amplification signals. The results were highly accurate with a detection limit of approximately 3 log cfu/g without culturing. The detection time for the five target food-borne pathogens on the fresh-cut cantaloupe and lettuces was found to be 24 hours. This highlights the great efficacy of the detection system to rapidly monitor the pathogens on the fresh food items. Such a system can be easily incorporated as an efficient food surveillance system for checking the logistical distribution chain, the food at the processing stage, cleaning condition at the food manufacturing plants, transport, sales and more. The technology is considered valuable as it supports the safety of fresh agricultural products, reducing the overall wastage of food due to infectious pathogens.