Applications of upconversion nanoparticles in analytical and biomedical sciences: a review.

Lanthanide-doped upconversion nanoparticles (UCNPs) have gained more attention from researchers due to their unique properties of photon conversion from an excitation/incident wavelength to a more suitable emission wavelength at a designated site, thus improving the scope in the life sciences field. Due to their fascinating and unique optical properties, UCNPs offer attractive opportunities in theranostics for early diagnostics and treatment of deadly diseases such as cancer. Also, several efforts have been made on emerging approaches for the fabrication and surface functionalization of luminescent UCNPs in optical biosensing applications using various infrared excitation wavelengths. In this review, we discussed the recent advancements of UCNP-based analytical chemistry approaches for sensing and theranostics using a 980 nm laser as the excitation source. The key analytical merits of UNCP-integrated fluorescence analytical approaches for assaying a wide variety of target analytes are discussed. We have described the mechanisms of the upconversion (UC) process, and the application of surface-modified UCNPs for in vitro/in vivo bioimaging, photodynamic therapy (PDT), and photothermal therapy (PTT). Based on the latest scientific achievements, the advantages and disadvantages of UCNPs in biomedical and optical applications are also discussed to overcome the shortcomings and to improve the future study directions. This review delivers beneficial practical information of UCNPs in the past few years, and insights into their research in various fields are also discussed precisely.

Photo-induced reactions for disassembling of coloaded photosensitizer and drug molecules from upconversion-mesoporous silica nanoparticles: An effective synergistic cancer therapy.

Photodynamic therapy is an emerging noninvasive cancer treatment approach, which requires a photosensitizer (PS), light, and molecular oxygen. In this study, we have successfully fabricated a dual nature (pH- and reactive-oxygen-species-responsive) upconversion nanoparticles (UCNPs) to utilize coloaded doxorubicin (DOX) and chlorin e6 (Ce6) with high antitumor efficacy. The model anticancer drug (DOX) and PS (Ce6) were conjugated in a ratio of 1:1 (w:w), and then loaded on the surface of UCNPs@mesoporous silica (mSiO2) (85.63 ± 9.87 nm). Cellular uptake could be achieved by either increased permeability or ionic effect of UCNPs@mSiO2, where Ce6 controlled the DOX release under a near-infrared (NIR) laser irradiation at 980 nm. A cytotoxicity analysis revealed that the dual-responsive UCNPs@mSiO2 could successfully deliver DOX and Ce6 at the tumor site, causing cell death with a high efficiency. This study shows that the modified UCNPs@mSiO2 is a promising system to realize NIR-light-triggered PS and drug delivery approach to improve synergistic therapies in vitro and in vivo, in the future.

Psycho-social predictors of acculturative stress and adjustment in Pakistani Institutions.

OBJECTIVES: The main objective of study was to investigate the effect of psycho-social predictors on acculturative stress and adjustment in Pakistani institutions. METHODS: The study was carried out from November 15, 2016 to January 18, 2019. For this purpose data was collected from 450 international students who were studying in public and private sector universities of Pakistan and who experienced acculturative stress. The instruments include Relationship Assessment Scale, Acculturative Stress Scale for International, Psychological Adaptation Scale, and Revised Socio Cultural Adaptation Scale. The proposed model was tested by using SPSS (Version-23) and AMOS (Version-9). RESULTS: Findings of the study revealed that relationship satisfaction (p<0.05), length of stay (p<0.05), and financial support (p<0.05) significantly negatively predicted acculturative stress. Financial support significantly positively predicted psychological adjustment (p<0.05). Employment status did not predict acculturative stress, psychological and socio-cultural adjustment (p>0.05). Moreover, all psycho-social predictors did not show effect on socio-cultural adjustment among international students (p>0.05). CONCLUSION: It can be concluded that general relationship satisfaction, more length of stay in host country, and financial support are very important for international students to manage their acculturative stress and to adjust better in a new cultural environment.

Assembly of 6-aza-2-thiothymine on gold nanoparticles for selective and sensitive colorimetric detection of pencycuron in water and food samples.

A facile and novel nanosensor analytical strategy was developed for the colorimetric detection of pencycuron fungicide in rice, potato, cabbage, and water samples based on the pencycuron-induced aggregation of 6-aza-2-thiothymine-functionalized gold nanoparticles (ATT-AuNPs). The ATT-AuNPs exhibited good stability and were characterized with UV-visible spectroscopy, Fourier transform infrared (FT-IR) spectrometry, field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), dynamic light scattering (DLS), and zeta potential techniques. The addition of pencycuron facilitated strong non-covalent interactions (electrostatic, van der Waals, and H bonding) between pencycuron and ATT-AuNPs, inducing a significant red shift in the surface plasmon resonance (SPR) peak of ATT-AuNPs along with a color change from red to blue. A linear equation was established between absorption ratio (A720/A528) and pencycuron concentration (2.5-100 µM) with a correlation coefficient (R2) of 0.9915. The detection limit was calculated to be 0.42 µM, which was much lower than that of other analytical methods. The designed ATT-AuNP serves as a promising nanosensor for the rapid, simple, and selective label-free colorimetric detection of pencycuron in rice, potato, cabbage, and water samples, is highly sensitive, and does not require sophisticated instruments, tedious sample preparations, and time-consuming separation and pre-concentration procedures.

A facile hydrothermal synthesis of highly luminescent NaYF4:Yb3+/Er3+ upconversion nanoparticles and their biomonitoring capability.

Using a facile hydrothermal procedure, hydrophilic NaYF4: Yb3+/Er3+ nanoparticles (NPs) have been prepared as lanthanide-doped upconversion (UC) materials exhibiting different morphologies, crystal phases and luminescence intensity. The upconversion nanoparticles (UCNP) were characterized by means of electron microscopy and spectroscopy, X-ray diffraction (XRD) and photoluminescence analysis. The molar concentration of reactants and volumes of NaF affect the shapes and uniformity of the synthesized NPs. These parameters also have influence on crystal phase and luminescence intensity of the NPs. Adjusting hydrothermal reaction time and dopant concentration also enable the synthesis of NPs with strong UC luminescence. The as-prepared UCNP showed cellular nontoxicity to HeLa cells, and thus they are capable as promising agents for biological imaging.

Efficacy of Surah Al-Rehman in Managing Depression in Muslim Women.

The study empirically investigated the idea that Quranic verses (Surah Al-Rehman) can help manage depression. Abdullah Ibn Mas'ud (radiAllahu anhu) reported that the Prophet (salAllahu alayhi wasalam) said, "Everything has an adornment, and the adornment of the Qur'an is Surah Al-Rehman." Surah Al-Rehman is the most rhythmic surah of the Quran, so it was used for our experimental study. The idea of the study was drawn from the premise that music therapy helps reduce depression. The objective of the present study was to investigate the efficacy of Surah Al-Rehman for managing depression in Muslim women admitted for treatment of major depressive disorder in a psychiatry ward of a government hospital. It was hypothesized that women diagnosed with severe depression in the treatment group will have reduced level of depression as compared to control group at post-assessment level. It was further hypothesized that the amount of decrease in depression in treatment group at the post-assessment level will be greater as compared to the control group. A purposive sample of 12 female patients diagnosed with depression was randomly assigned to the treatment group (n = 6) and control group (n = 6). Assessment was done at pre- and post-level by using Beck Depression Inventory-II. Both groups did not significantly differ on pre-assessment depression scores. Twelve structured group sessions of 22 min, two times a day, were conducted for a period of 4 weeks with the groups. Treatment group was made to listen to Surah Al-Rehman recited by Qari Abdul Basit, and control group was exposed to music used for relaxation and treatment of depression. Wilcoxon signed ranks test was used to find the within-group differences between pre- and post-assessment scores. Both groups had decreased level of depression at post-assessment level, so it was important to assess if there was any difference in level of decrease. Mann-Whitney U test for comparison of groups on level of decrease at the post-assessment level endorsed that treatment group had significantly greater decrease than control group on depression. Our study highlights the efficacy of Surah Al-Rehman as a remedy to reduce depression. The Holy Quran intones, "This sacred book is 'shifa' for its followers." Hence, we recommend that researchers should focus on finding remedies for other psychological and physical diseases from Quranic verses. An exploration of possible mechanism (such as activated cognitions or associated emotions while listening to Quran) through which effects of recitation are reached, can also be subject of investigation for forthcoming studies.

Morphological evolution of upconversion nanoparticles and their biomedical signal generation.

Advancements in the fabrication of upconversion nanoparticles (UCNPs) for synthetic control can enable a broad range of applications in biomedical systems. Herein, we experimentally verified the role of the hydrothermal reaction (HR) time in the synthesis of NaYF4:20%Yb3+/3%Er3+ UCNPs on their morphological evolution and phase transformation at different temperatures. Characterizations of the as-prepared UCNPs were conducted using X-ray diffraction (XRD), electron microscopy and spectroscopy, and thermogravimetric and upconversion (UC) luminescence analysis. We demonstrated that determining the optimal HR time, also referred to here as the threshold time, can produce particles with good homogeneity, hexagonal phase, and UC luminescence efficiency. Subsequently, the polymer coated UCNPs maintained their original particle size distribution and luminescence properties, and showed improved dispersibility in a variety of solvents, cellular nontoxicity, in vitro bioimaging, and biocompatibility as compared to the bare UCNP. Besides this, polyacrylic acid conjugated UCNPs (UCNP@PAA) also revealed the strong anticancer effect by conjugating with doxorubicin (DOX) as compared to the free DOX. Based on these findings, we suggest that these particles will be useful in drug-delivery systems and as in vivo bioimaging agents synchronously.

Synthesis of fluorescent silicon quantum dots for ultra-rapid and selective sensing of Cr(VI) ion and biomonitoring of cancer cells.

A facile one-step synthetic approach was developed for fabrication of fluorescent silicon quantum dots (Si QDs) and used as a probe for fluorescence detection of hexavalent chromium (Cr (VI)) in environmental water samples. The as-prepared Si QDs exhibit a strong fluorescence emission peak at 520 nm with a quantum yield of 14.2%. The fluorescent Si QDs were rapidly produced by using ascorbic acid as a reductant at 55 °C. The emission peak of Si QDs at 420 nm was effectively quenched upon the addition of Cr(VI). The Si QDs acted as the best fluorescent probe for the detection of Cr(VI) at PBS pH 7.4. The developed probe possessed a good linear correlation (R2 = 0.992) between Cr(VI) concentration (1.25-40 µM) and the (F0-F)/F0 values with a detection limit of 0.65 µM. Furthermore, the Si QDs served as a bio-probe for fluorescence imaging of A549 lung cancer cells and cell viability results confirmed the good biocompatible nature of Si QDs. The as-fabricated Si QDs show several advantages such as rapidity, selectivity and biocompatibility for sensing of Cr(VI) and imaging of A549 cells, which opens a facile analytical platform for environmental and bioimaging applications.

Gold-copper nanoshell dot-blot immunoassay for naked-eye sensitive detection of tuberculosis specific CFP-10 antigen.

Herein, a straightforward and highly specific dot-blot immunoassay was successfully developed for the detection of Mycobacterium tuberculosis antigen (10 kDa culture filtrate protein, CFP-10) via the formation of copper nanoshell on the gold nanoparticles (AuNPs) surface. The principle of dot-blot immunoassay was based on the reduction of Cu2+ ion on the GBP-CFP10G2-AuNPs conjugates, which has gold binding and antigen binding affinities, simultaneously, favouring to appear red dot that can be observed with naked-eye. The dot intensity is proportional to the concentration of tuberculosis antigen CFP-10, which offers a detection limit of 7.6 pg/mL. The analytical performance of GBP-CFP10G2-AuNPs-copper nanoshell dot-blot was superior than that of conventional silver nanoshell. This method was successfully applied to identify the CFP-10 antigen in the clinical urine sample with high sensitivity, specificity, and minimized sample preparation steps. This method exhibits great application potential in the field of nanomedical science for highly reliable point-of-care detection of CFP-10 antigen in real samples to early diagnosis of tuberculosis.

Data on rhizosphere pH, phosphorus uptake and wheat growth responses upon TiO2 nanoparticles application.

In this study, the data sets and analyses provided the information on the characterization of titanium dioxide nanoparticles (TiO2 NPs), and their impacts on rhizosphere pH, and soil-bound phosphorus (P) availability to plants together with relevant parameters. For this purpose, wheat (Triticum aestivum L.) was cultivated in the TiO2 NPs amended soil over a period of 60 days. After harvesting, the soil and plants were analyzed to examine the rhizosphere pH, P availability in rhizosphere soil, uptake in roots and shoots, biomass produced, chlorophyll content and translocation to different plant parts monitored by SEM and EDX techniques in response to different dosages of TiO2 NPs. The strong relationship can be found among TiO2 NPs application, P availability, and plant growth.

Synthesis of upconversion nanoparticles conjugated with graphene oxide quantum dots and their use against cancer cell imaging and photodynamic therapy.

Multifunctional nanocomposite has a huge potential for cell imaging, drug delivery, and improving therapeutic effect with less side effects. To date, diverse approaches have been demonstrated to endow a single nanostructure with multifunctionality. Herein, we report the synthesis and application of core-shell nanoparticles composed with upconversion nanoparticle (UCNP) as a core and a graphene oxide quantum dot (GOQD) as a shell. The UCNP was prepared and applied for imaging-guided analyses of upconversion luminescence. GOQD was prepared and employed as promising drug delivery vehicles to improve anti-tumor therapy effect in this study. Unique properties of UCNPs and GOQDs were incorporated into a single nanostructure to provide desirable functions for cell imaging and drug delivery. In addition, hypocrellin A (HA) was loaded on GOQDs for photo-dynamic therapy (PDT). HA, a commonly used chemotherapy drug and a photo-sensitizer, was conjugated with GOQD by π-π interaction and loaded on PEGylated UCNP without complicated synthetic process, which can break structure of HA. Applying these core-shell nanoparticles to MTT assay, we demonstrated that the UCNPs with GOQD shell loaded with HA could be excellent candidates as multifunctional agents for cell imaging, drug delivery and cell therapy.

Metallic Nanoparticle (TiO2 and Fe3O4) Application Modifies Rhizosphere Phosphorus Availability and Uptake by Lactuca sativa.

Application of engineered nanoparticles (NPs) with respect to nutrient uptake in plants is not yet well understood. The impacts of TiO2 and Fe3O4 NPs on the availability of naturally soil-bound inorganic phosphorus (Pi) to plants were studied along with relevant parameters. For this purpose, Lactuca sativa (lettuce) was cultivated on the soil amended with TiO2 and Fe3O4 (0, 50, 100, 150, 200, and 250 mg kg(-1)) over a period of 90 days. Different techniques, such as scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Raman, and Fourier transform infrared spectroscopy (FTIR) were used to monitor translocation and understand the possible mechanisms for phosphorus (P) uptake. The trends for P accumulation were different for roots (TiO2 > Fe3O4 > control) and shoots (Fe3O4 > TiO2 > control). Cystine and methionine were detected in the rhizosphere in Raman spectra. Affinities of NPs to adsorb phosphate ions, modifications in P speciation, and NP stress in the rhizosphere had possibly contributed to enhanced root exudation and acidification. All of these changes led to improved P availability and uptake by the plants. These promising results can help to develop an innovative strategy for using NPs for improved nutrient management to ensure food security.

Experiences and coping behaviours of adolescents in Pakistan with alopecia areata: an interpretative phenomenological analysis.

The study explored experiences of adolescents aged 15-19 with alopecia areata (AA) and investigated their accounts of coping behaviours. Interpretative Phenomenological Analysis was used to provide an in-depth and holistic perspective of their accounts. Semi-structured interviews were undertaken with a volunteer sample of eight respondents diagnosed with AA. Four key themes were identified: loss (self/social), concerns (physical/future), negative (emotions/thoughts), and coping styles (adaptive/maladaptive). Females experienced greater feelings of loss, were more concerned about their looks and their future, and reported more negative thoughts and emotions. Females felt angry and blamed God for their fate; males blamed both their fate and luck. Action-oriented and practical coping styles were adopted by all of them. After the realization that initial coping behaviours were ineffective, self-distraction, acceptance, and humour were used. Psychological relief followed with the practice of religion and planning for treatments to be undertaken in the future. The findings here are similar to research conducted in the West, though with more emphasis on religion. Health care providers and student counsellors need to understand the negative psychosocial consequences for adolescents living with a visible disfigurement and provide appropriate psychological and social support.

POSITIVE AND NEGATIVE PSYCHOLOGICAL CORRELATES, GENDER SPECIFIC AND TRADITIONAL FACTORS FOR FIRST ONSET ANGINA IN A SAMPLE OF PAKISTANI WOMEN.

BACKGROUND: Coronary Heart Disease (CHD) occurs to a greater extent in developed than developing countries like Pakistan. Our understanding of risk factors leading to this disease in women, are largely derived from studies carried out on samples obtained from developed countries. Since prevalence of CHD in Pakistan is growing, it seems pertinent to infer risk and protective factors prevalent within the Pakistani women. This case control study investigated the role of psychological, traditional and gender specific risk and protective factors for Angina in a sample of Pakistani women aged between 35-65 years. METHODS: Female patients admitted with first episode of Angina fulfilling the study inclusion/exclusion criteria were recruited within the first three days of stay in the hospital. One control per case matched on age was recruited. Translated versions of standardized tools: Life Orientation Test (LOT), The Hope Scale, Subjective Happiness Scale and Depression, Anxiety and Stress Scale (DASS) were used to measure the psychological variables. Information on medical conditions like diabetes, hypertension, family history of IHD, presence and absence of menopause and use of oral contraceptive pills was obtained from the participants. Body Mass Index for cases and controls was calculated separately with the help of height and weight recorded for the participants. RESULTS: Multivariate logistic regression analyses revealed that depression, anxiety and stress are risk factors, were as optimism and hope are protective predictors of Angina. 64% and 85% of variance in Angina were attributed to psychological factors. Menopause, diabetes and hypertension are significantly associated with the risk of Angina, explaining 37% and 49% of variance in Angina. The study provides evidence for implementation of gender specific risk assessment and preventive strategies for Angina. The study gives directions for large scale prospective, epidemiological, longitudinal as well as interventional studies, to be tailored for indigenous population and secondly development and standardization of measures to appraise psychological factors of Angina prevalent within the Pakistani population.

Psychological correlates of early onset of ischemic heart disease in a sample drawn from a Pakistani population.

Even in the presence of substantial empirical evidence which proves that psychological risk factors play a significant role in onset of ischemic heart disease (IHD), in Pakistan researchers have not paid much attention to exploring these factors. This research was mainly undertaken to investigate whether psychological factors such as stress, anxiety, depression, anger, and hostility in their intense states are prevalent within the indigenous patients with IHD. It was hypothesized that: High levels of perceived stress will significantly increase risk for IHD versus lower levels of perceived stress; high levels of anxiety will significantly increase the risk for IHD versus lower levels of anxiety; high levels of depression will increase the chances of IHD versus lower levels. Likewise, it was proposed that elevated trait anger will significantly increase risk for IHD versus lower levels of trait anger and that higher levels of hostility significantly increase risk for IHD versus lower levels. A case-control research design was employed to conduct this study. To investigate the association of the abovementioned factors with IHD and to find whether these factors differ between cases and controls, we solicited a sample of 190 patients with confirmed diagnosis of IHD and 380 age- and gender-matched community controls, who were free of IHD, aged 35 to 55 years. Standardized tools to measure psychological factors were translated and semistandardized into the national language and their psychometric properties were predetermined before use in this study. To infer the proposed hypotheses, multivariate binary logistic regression analysis was carried out. Results highlight significant association between stress, depression, anxiety, anger, and IHD. Implications for the implementation of routine screening for psychological factors, particularly stress, depression and anger, are proposed.

Dietary predictors of early-onset ischaemic heart disease in a sample drawn from a Pakistani population.

OBJECTIVE: A relationship between dietary pattern and ischaemic heart disease (IHD) has long been established through empirical research. It is well documented that an unhealthy diet-rich in animal products (eggs and meat), salt, fried and salty food, ghee and butter and low in fruit, vegetables and fish-is associated with a risk of IHD. However, limited empirical evidence exists from studies conducted in Pakistan, so this study was designed to explore the association of dietary pattern with risk of IHD in this country. DESIGN: Case-control study. SETTING: 190 cases with a diagnosis of first onset of angina and myocardial infarction and 380 age- and gender-matched community controls were recruited from five major hospitals in the city of Lahore, Pakistan. METHOD: A Food Frequency Questionnaire was used to gather information on dietary patterns from the study sample (age 35-55), who provided written consent to participate. RESULTS: Binary logistic regression analysis revealed that eggs, sweets, butter, desi ghee, desserts and beef were significant risk factors for IHD, and fish and fruit were significant protective dietary predictors of IHD. CONCLUSIONS: 50-73% of variance in IHD due to dietary pattern can be predicted with 91.8% accuracy within the study sample. The study lays ground for future research, as well as providing help in planning preventive dietary strategies to counter the escalating burden of IHD in Pakistan.

Neuropsychological functions in epilepsy patients.

BACKGROUND: Neuropsychological impairment can be associated with epilepsy and its different types. The present study investigated gender differences in neuropsychological functions in epileptic patients. It was hypothesized that neuropsychological functioning will be different in male as compared to female epileptic patients. It was also hypothesized that there are significant gender differences among male and female epileptic patients in depression, somatic complaints, memory, communication, aggression and motor impairment. In addition it was hypothesized that neuropsychological functioning among patients diagnosed with different types of epilepsy; grand mal, petit mal, complex partial and generalized tonic clonic will be different. METHOD: A sample of 60 patients was recruited from different hospitals situated in the city of Lahore through purposive sampling technique. To assess neuropsychological functions, Neurobehavioral Functioning Inventory (NFI) was used. NFI was translated and back translated through the process of validation and final version of the scale in Urdu was obtained for use in the study. ANOVA and Student's t-test were employed to infer the proposed hypotheses. RESULT: There is significant difference in neuropsychological functioning between male and female epileptic patients on only somatic complaints. Females were found to reveal greater somatic complaints compared to their male counterparts. There are significant differences in neuropsychological functioning among patients diagnosed with different types of epilepsy. CONCLUSIONS: The study lays ground for future research and holds implications for the implementation of gender based neuropsychological interventions.