Cotton Swab Research Articles

A Prototype 3D Printed Suction Port Adapter for a Wireless Otoendoscope

ABSTRACTObjective: To design and fabricate a suction port adapter to use various sizes of suction cannulaswith a wireless otoendoscope enabling ear cleaning under endoscopic guidance demonstrated using an ear examination simulator. Methods:Design: Instrument InnovationSetting: Tertiary Private Training HospitalPatient: Ear Examination Simulator Results: The fabricated suction port adapters were able to hold the wireless otoendoscope and suction cannulas together, allowing simultaneous inspection of the ear canal and suctioning of ear canal debris using the Ear Examination Simulator Conclusion: Our prototype 3D-printed suction port adapters for a wireless otoendoscope mayimprove ear cleaning by enhancing the accuracy of suctioning debris and decreasing durationsince they hold the suction cannulas in place under endoscopic guidance. They may aid ENTphysicians in easier visualization and simultaneous ear cleaning of patients and improve earcleaning techniques and times, especially among less experienced physicians, but actual clinicaltrials are needed to confirm this.

Karakteristik Pasien Otitis Eksterna di Poli THT-KL Rumah Sakit Universitas Mataram Periode Oktober 2022 – Oktober 2023

Background: Otitis externa (OE) is one of the most common diseases encountered in otorhinolaryngology practice. OE is an inflammation of the external acoustic canal (CAE). Around 10% of people experience OE at some stage of their lives. OE is related to several factors, one of which is excessive ear cleaning with cotton buds. Some people are still unfamiliar with the dangers of ear cleaning. Therefore, understanding OE is very important. This study aims to improve public understanding of OE by knowing the characteristics of OE patients in the ENT clinic of Mataram University Hospital. Methods: This study is a retrospective descriptive-analytic study. Data were obtained from the medical records of ENT clinic patients at the University of Mataram Hospital from October 2022 to October 2023. Samples were taken using the total sampling method. Data were analyzed using quantitative descriptive statistics. Results: A total of 164 samples were analyzed and it was found that most OE patients were female (61.0%). Most OE patients were in the age group under 50 years (79.9%) with a mean age of 33.93 ± 17.64 years. The most common clinical symptom complained by OE patients was ear pain (73.8%), followed by itching (48.8%), discharge (36.6%), buzzing (17.7%), decreased hearing (15.9%), and ear fullness (14.6%). The location of complaints was mostly felt in the left ear (43.9%). Conclusion: OE cases in the ENT clinic of Mataram University Hospital are most often found in the female population, the age group is under 50 years, and the most clinical symptoms are ear pain, with the most complaints felt in the left ear.

A smartphone-based fluorescent biosensor with metal-organic framework biocomposites and cotton swabs for the rapid determination of tetrodotoxin in seafood

BackgroundTetrodotoxin (TTX) is a potent neurovirulent marine biotoxin that is present in puffer fish and certain marine animals. It is capable of causing severe neurotoxic symptoms and even death when consumed through contaminated seafood. Due to its high toxicity, developing an effective assay for TTX determination in seafood has significant benefits for food safety and human health. Currently, it remains challenging to achieve on-site determination of TTX in seafood. To facilitate mass on-site assays, more affordable technologies utilizing accessible equipment that require no skilled personnel are needed. ResultsA smartphone-based portable fluorescent biosensor is proposed for TTX determination by using metal-organic framework (MOF) biocomposites and cotton swabs. Oriented antibody (Ab)-decorated and fluorescent quantum dot (QD)-loaded MOF biocomposites (QD@MOF*Ab) are rapidly synthesized for binding targets and fluorescent responses by utilizing the tunability of zinc-based MOF. Moreover, facile Ab-immobilized household cotton swabs are utilized as TTX capture tools. TTX forms sandwich immune complexes with QD@MOF*Ab probes, achieving signal amplification. These probes are excited by a portable device to generate bright fluorescent signals, which can be detected by the naked eye, and TTX quantitative results are obtained using a smartphone. When observed with the naked eye, the limit of detection (LOD) is 0.4 ng/mL, while intelligent quantitation presents an LOD of 0.13 ng/mL at logarithmic concentrations of 0.2–400 ng/mL. SignificanceThis biosensor is convenient to use, and an easy-to-operate analysis is completed within 15 min, thus demonstrating excellent performance in terms of detection speed and portability. Furthermore, it successfully determines TTX contents in puffer fish and clam samples, demonstrating its potential for monitoring seafood. Herein, this work provides a favorable rapid sensing platform that is easily portable.

Bacteriological Study of Post-Operative Wound Infection and its Antibiograms

INTRODUCTIONPostoperative wound infections are a significant complication of surgical procedures, which increases morbidity, mortality, prolonged hospital stay, and increased healthcare costs. The study was undertaken with an aim to investigate the etiological agents of postoperative wounds and their sensitivity to commonly used antibiotics. MATERIAL AND METHODSThis study was a descriptive cross-sectional prospective study, carried out at Universal College Of Medical Sciences-Teaching Hospital, Bhairahawa, Nepal, on 100 postoperatively wounded infected cases, during April 2023 – August 2023, Non Probability sampling method (Purposive sampling) was used, and specimens were collected by sterile cotton swabs and pus was aspirated with a sterile needle and syringe and processed using standard bacteriological techniques. Antibiotic sensitivity test was conducted by disc diffusion (Kirby-Bauer) method. RESULTSPostoperative wound infections caused by Gram negative bacilli were more frequent and predominant pathogens involved were Pseudomonas aeruginosa, followed by Klebsiella spp and Enterobacter aerogenes. Among Gram positive bacteria Staphylococcus aureus was predominant. Gram positive cocci were highly sensitive to Ampicillin, and Gram negative bacilli were highly sensitive to Ceftazidime, Gentamicin, and Amikacin. Coagulase negative staphylococci were resistant to all drugs tested. CONCLUSIONPseudomonas aeruginosa was the commonest etiological agent for postoperative wound infections. Gram positive cocci and E.coli were highly sensitive to Ampicillin and Gram negative bacilli were highly sensitive to Ceftazidime, Gentamicin, Amikacin. Staphylococcus aureus was resistant to vancomycin and Teicoplanin and coagulase staphylococci were resistant to all drugs tested. Gram negative bacilli were resistant to Polymyxin B and Tigecycline. Increasing resistance to commonly used antibiotics warrants the judicious use of antibiotics and establishment of antibiotic policy in the hospital.

Bacterial Colonization of Mobile Phones: Myth or Reality.

Introduction Bacteria tend to persist on mobile phones for longer durations causing hospital-acquired infections. This is primarily because mobile phones have become an extended hand to healthcare workers due to their unavoidable utilization and the lack of sanitization after use in wards. Methods A questionnaire was used to assess the usage and disinfection practices of mobile phones among medical students regularly attending the wards of a teaching hospital. Culture was done to assess the presence of bacteria and their resistance to antibiotics. Three sterile cotton swabs were performed for each mobile phone. If growth was present, then a culture smear was made, and the type of bacteria was assessed. Participants received subsequent education on the disinfection of phones according to standard disinfection protocol. The main objective of the study was to determine the presence of bacteria on students' mobile phones and its resistance to antibiotics. Results A total of 103 medical students took part in the study, which included 51 males and 52 females. It was found that all the students used their mobile phones at all times in wards and 43% of them carried their phones to washrooms. Out of all the students surveyed, only 23% of students had regularly disinfected their phones. Bacteria were present on all mobile phones sampled. Among these, 98.05% had Gram-positive bacteria, 82.52% had Gram-negative bacilli, 33.98% had Bacillaceae, and 8.73% had vancomycin-resistant enterococcus (VRE). Among participants who did not disinfect their phones, 95.89% and 97.59% had methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive Staphylococcus aureus (MSSA), respectively. Conclusion Following standard disinfection protocols is the need of the hour to reduce hospital-acquired infections.

The Severity of Tooth Surface Loss in Adult Patients Presenting to a Private Dental Hospital

This study aimed to assess the severity of tooth surface loss (TSL) in adult patients at a private dental hospital for 6 months. This research explored the severity of TSL using the Smith and Knight Tooth wear index (TWI). Study participants underwent intraoral examination in dental chairs with adequate lighting using a mouth mirror. Prior to examination, sterile cotton swab was used to clean and dry the teeth and to eliminate any plaque residue. Each tooth surface (buccal, lingual, cervical and occlusal/incisal) were evaluated using the TWI and documented on the research proforma. Only the most affected teeth and teeth surfaces were noted in a patient. A total of 320 patients were observed between ages (18-40 years), out of which 140 had tooth wear according to TWI. The male patient had a ratio of 40.91% while female were 50.08%. The mandibular anterior teeth had score 2 in 97.1% of the patients and maxillary premolars had score 1 and 2 which were 96.4% and 92.9% respectively. The occlusal surface was involved in 58% of maxillary teeth and 100% in mandibular teeth. Our study indicates that the mandibular anterior occlusal surfaces are particularly susceptible to the impacts of tooth wear. This may lead to aesthetic concerns, exposure of pulp with advanced wear and occlusal imbalance, which will require extensive treatment. Hence, it is imperative to raise awareness among individuals regarding the early indicators and symptoms of tooth wear.

A New Fluorene-Based Fluorescent Probe for Recognition of Hypochlorite Ions and its Applications.

Oxidative stress is a trigger for many diseases and occurs with the unstable hypochlorite (ClO-), known as one of the reactive oxygen species (ROS) in organisms. Then, HOCI is acknowledged as an oxidizing species that eliminates a variety of environmental pollutants. Hence, the development of novel methodologies for the selective and precise identification of HOCl/ ClO- is considered to be of utmost importance. In this study, the design, characterization, and applications of a fluorene-based fluorescent probe (FHBP) dependent on the ESIPT mechanism with a "turn-on" response for the sensitive/selective determination of ClO- against other competing samples were reported. The experimental results indicated that the detection limit for ClO-could be quantitatively determined by the probe to be 8.2 × 10-7M. The binding constant of the probe FHBP with ClO- was computed as 9.75 × 103M-1. In addition, the response time of FHBP was appointed to be 30s, indicating a rapid reaction with ClO-. It has also been demonstrated that this probe can be successfully used for the detection of ClO- on filter papers, TLC sheets, cotton swabs, and real samples.

Reversible NIR emitting fluorescent sensor with biocompatible and large Stokes shift for the Zn2+ in environmental samples and living cells

Herein, a simple dicyanoisophoron-based near-infrared (NIR) fluorescent sensorIQhas beendesigned and constructed for the rapid recognition of Zn2+in environmental samples and living systems. The synthesized NIR sensorIQin H2O/EtOH/ (1/9, v/v) displayed excellent recognition performances towards Zn2+including nano-molar detection limit (60.5 nM)and a large Stokes shift (173 nm). SensorIQwas successively applied to realize the determination of Zn2+in smartphone applications.Furthermore,IQ-loaded test strips, cotton swabs, and polysulfone capsules were able to quickly determine the presence of Zn2+. Besides,IQwas effectively employed to monitor Zn2+content in actual environmental samples (tap, pure, and lake water samples, rice, and potato). Additionally, the imaging potential ofIQwas utilized to visualize Zn2+in living cells. The results from these applications indicated that the designed probeIQis hopeful to be utilized for the recognition of Zn2+in multiple applications.

Acceptability of digital vending machines to improve access to sexual and reproductive health in Brighton, UK: a qualitative analysis

IntroductionSexual health remains a public health priority and relies on widely available testing to enable prompt diagnosis and treatment. Technology-based approaches to distribute tests have potential to increase access and...

Efficacy of verbal suggestion, verbal suggestion with a tuning fork, and verbal suggestion with a cotton swab for inducing the paroxysmal event during video-EEG recording in children with suspected psychogenic nonepileptic seizures

IntroductionVideo-electroencephalogram (EEG) with suggestion is widely considered the gold standard for diagnosing psychogenic nonepileptic seizures (PNES). However, ethical concerns and uncertainties persist regarding the most minimally invasive and least deceptive suggestion approach. Materials and methodsIn an open-label randomized controlled trial, we evaluated the effectiveness of three suggestion methods (verbal suggestion, verbal suggestion with a tuning fork, and verbal suggestion with a cotton swab) during short-term video-EEG (STVEEG) recordings to induce PNES in children aged 5–18 years. If the paroxysmal event couldn't be elicited with the assigned method, alternative techniques were employed. ResultsOut of 97 initially screened children, 75 were enrolled, with 25 in each group. The efficacy of all three suggestion methods was comparable in reproducing paroxysmal events (success rate of 16/25, 17/25 and 17/25 in verbal suggestion only, verbal suggestion with tuning fork and sterile cotton swab group respectively, p = 0.83) and the time required for induction (median of 2, 3 and 3 min respectively, p = 0.21). After trying alternative methods, 20 %, 12 %, and 12 % more patients in these three groups, respectively, were able to reproduce the paroxysmal event, with the differences not reaching statistical significance (p = 0.74). The assigned induction method or the success/failure of event reproduction did not significantly impact clinical outcomes at 12 weeks, and none of the patients in whom PNES could not be reproduced during STVEEG were later found to have an organic cause. Only the presence of psychiatric comorbidity independently predicted successful event reproduction during STVEEG, with statistical significance even after adjusting for other variables (p = 0.03). ConclusionThe efficacy of verbal suggestion alone in inducing paroxysmal nonepileptic seizures is on par with using a tuning fork or cotton swab in conjunction with verbal suggestion during STVEEG.

Preliminary study on the diversity and quantity analysis of oral bacteria according to the sampling methods

Objectives: Oral bacterial samples included subgingival, supragingival, and saliva plaques. As the diversity and number of microorganisms deffer depending on the area of the oral cavity and the method used, an appropriate and reliable collection method is important. The present study investigated oral bacterial sampling methods. Methods: Supragingival dental plaque was collected from the buccal and lingual tooth surfaces of study participants using sterilized cotton swabs. Plaques were collected from the subgingival area using a sterilized curette. Bacterial genomic DNA was extracted using MagNA Pure 96 DNA and Viral NA low-volume kits. Real-time polymerase chain reaction (PCR) was performed using the PowerCheck™ Periodontitis Pathogens Multiplex Real-time PCR kit. Results: Aggregatibacter actinomycetemcomitans, Prevotella intermedia, and Fusobacterium nucleatum of the orange complex were not observed in the subgingival biofilms of all study participants. For Porphyromonas. gingivalis, a significant correlation was observed between supragingival, subgingival, and total tooth surface biofilms. Compared to the supragingival and subgingival biofilmss, total tooth surface biofilm exhibited the highest bacterial count when the inswabbing method was used. Conclusions: Based on these findings, the supragingival swab method is recommended for oral bacterial research.

Kegiatan Pemeriksaan Fisik Kesehatan Telinga dalam Rangka Deteksi Dini Otitis Media Supuratif Kronik pada Populasi Lanjut Usia

Maintaining overall body health, including ear hygiene, is very important. The ear is an important organ in the human balance and hearing system. The human ear has self-cleaning capabilities, facilitated by cerumen, which occurs naturally to protect and keep the ear canal moist. However, too much or too little cerumen production can cause complaints such as decreased hearing, itching, and dry ear canals. Cleaning your ears yourself, which often involves inserting objects into the ear canal, can be dangerous. Improper use of cotton buds can push the cerumen deeper, causing blockages and increasing the risk of injury. This activity employs the PDCA (Plan-Do-Check-Act) method to conduct ear health screening for cerumen and tympanic membranes on 61 participants at the Hana Nursing Home. The physical examination results revealed that we could not assess 6 (9.8%) right tympanic membranes, 8 (13.1%) left tympanic membranes, 19 (31.1%) right ear canals, and 21 (34.4%) right ear canals. The participant's left has prop cerumen. Increased awareness and physical examination of the ear, as early detection can improve ear health and prevent ear injury.

Isolation of avian influenza virus from backyard poultry population of tehsil Abbottabad, Khyber Pakhtunkhwa, Pakistan

The avian influenza virus is a highly contagious viral disease that predominantly impacts avian species, especially domestic birds like chickens, ducks, and turkeys. The study was conducted to isolate the avian influenza virus from domestic poultry breeds (Desi, Aseel, Fayoumi, and Golden) from backyard poultry population of the Tehsil Abbottabad from January to June 2023. A cross-sectional study was conducted in three rural and five urban areas of Tehsil Abbottabad Using sterile cotton swabs, 128 (tracheal and cloacal) swab samples were collected. The samples were labelled and stored in a brain-heart infusion medium, then transported to the National Reference Laboratory for Poultry Diseases in Islamabad using a thermostat shipment box. The samples were processed using a real-time reverse transcription polymerase chain reaction for avian influenza virus detection. This study concludes with a significant 9.38% prevalence percentage of avian influenza virus in Tehsil Abbottabad backyard poultry. The prevalence percentage of H9 was 83.33%, and that of H5 was 16.66%. The findings reveal the importance of implementing preventative measures to curb avian influenza outbreaks within the poultry population of the district. This study offers vital data for AIV research in 2023, guiding enhanced containment and prevention in backyard poultry to control avian influenza.

Sampling is decisive to determination of Leishmania (Viannia) species.

Accuracy of molecular tools for the identification of parasites that cause human cutaneous leishmaniasis (CL) could largely depend on the sampling method. Non-invasive or less-invasive sampling methods such as filter paper imprints and cotton swabs are preferred over punch biopsies and lancet scrapings for detection methods of Leishmania based on polymerase chain reaction (PCR) because they are painless, simple, and inexpensive, and of benefit to military and civilian patients to ensure timely treatment. However, different types of samples can generate false negatives and there is a clear need to demonstrate which sample is more proper for molecular assays. Here, we compared the sensitivity of molecular identification of different Leishmania (Viannia) species from Peru, using three types of sampling: punch biopsy, filter paper imprint and lancet scraping. Different composite reference standards and latent class models allowed to evaluate the accuracy of the molecular tools. Additionally, a quantitative PCR assessed variations in the results and parasite load in each type of sample. Different composite reference standards and latent class models determined higher sensitivity when lancet scrapings were used for sampling in the identification and determination of Leishmania (Viannia) species through PCR-based assays. This was consistent for genus identification through kinetoplastid DNA-PCR and for the determination of species using FRET probes-based Nested Real-Time PCR. Lack of species identification in some samples correlated with the low intensity of the PCR electrophoretic band, which reflects the low parasite load in samples. The type of clinical sample can directly influence the detection and identification of Leishmania (Viannia) species. Here, we demonstrated that lancet scraping samples consistently allowed the identification of more leishmaniasis cases compared to filter paper imprints or biopsies. This procedure is inexpensive, painless, and easy to implement at the point of care and avoids the need for anesthesia, surgery, and hospitalization and therefore could be used in resource limited settings for both military and civilian populations.

Detection of Multidrug Resistant <i>Staphylococcus aureus </i>at Morogoro Regional Referral Hospital, Tanzania

<i>Background: </i>Hospital settings are associated with constant introduction of pathogens which can be transmitted among workers by patients, and visitors, resulting into potential nosocomial infections. This study compared the carriage and pattern of drug resistant <i>S. aureus </i>among patients and on equipment in hospital setting at Morogoro Regional Referral Hospital (MRRH). <i>Methods:</i> A cross sectional study was conducted by collecting samples from the anterior nares using sterile cotton swabs from patients. Furthermore samples were collected from inanimate surfaces, ward door handles; wheelchairs; and trolleys. The samples were incubated on mannitol salt agar plates aerobically at 37°C for 24 hours. Antimicrobial susceptibility testing was done using; erythromycin, azithromycin, ofloxacin, gentamicin, ciprofloxacin and cefoxitin. Clindamycin inducible resistance was tested by D test as per CLSI (2019). Data analysis was carried using SPSS where Chi – square was used to compare the association of occurrence of resistance and source of isolation. <i>Results: </i>Out of 200 samples, 54 tested positive for <i>S. aureus </i>were from human while the prevalence of <i>S. aureus </i>in inanimate objects was high in beds 10 (40%). The AMR was observed more in azithromycin (26.3%) than other antimicrobials. The D-Test showed inducible clindamycin-resistant phenotype in 57.1% of the MRSA isolates. The maternity ward had the highest risk of being exposed to <i>S. aureus </i>contamination [OR = 9.9 (95% CI, 2.0-19.30), p = 0.01] and tables [OR = 4.6 (95% CI, 1.22-1.89, p= 0.03)]. The recovery wards were least likely to be contaminated with the result of four times likely to be contaminate for both patients and surfaces [OR = 5.1 (95% CI, 1.3-8.6), p= 0.04] when compared with other wards. <i>Conclusion: </i>This study presents some important findings on MRSA which is a global concern, the authors encourages more researches are done in MRSA for efficient availability in the AMR database.

β-Galactosidase-triggered in situ synthesis of yellow emitting silicon nanoparticle and its application in visual detection of E. coli O157:H7 and drug susceptibility test

The sensitive detection of foodborne pathogenic and rapid antibiotic susceptibility testing (AST) is of great significance. This paper reports the enzyme-triggered in situ synthesis of yellow emitting silicon nanoparticles (SiNPs) and the detection of Escherichia coli (E. coli) O157:H7 in food samples and the rapid AST. The rapid counting of E. coli O157:H7 has been achieved through direct visual observation, equipment detection, and smartphone digitalization. A simple detection platform based on smartphone senses and cotton swabs has been established. Meanwhile, rapid AST based on enzyme-catalyzed SiNPs can intuitively obtain colorimetric samples. This paper established a system for bacterial enzyme-triggered in situ synthesis of SiNPs, with high responsiveness, luminescence ratio, and specificity. The detection limit for E. coli O157:H7 can reach 100 CFU/mL during 5 h, and the recovery efficiency ranges from 90.14% to 110.16%, which makes it a promising strategy for the rapid detection of E. coli O157:H7 and AST.

Extension study of the assessment of aqueous cleaning on nBA/MMA and EA/MMA acrylic paints

Acrylic paints became popular among artists in the late 50′s. Some of the main conservation issues of these paints are inherent to their composition characteristics, for instance, their high sensitivity to water and a wide range of polar solvents. This makes difficult to stablish an accurate and respectful cleaning treatment for this kind of artworks. As reported on previous studies, the application of pH and conductivity adjusted solutions using accurate methods, such as confined on chemical gels, improved this kind of procedures.The aim of this work is to extend a previous study where the effect of water based cleaning treatments was tested on Liquitex acrylic paint mock-ups, and deepen on evaluating the alterations both on the surface and in the bulk of the paint film. In this paper, six acrylic commercial paints of two widely used paint brands, Titan Arts – Acrílico extrafino (Spain) and Hyplar Acrylic Colors® (USA), were selected to compare the effect of the cleaning treatment on their surface and binder matrix. Samples were prepared using Mylar sheets and left to dry in a dark and dust-free environment for three years. Adjusted water solutions were applied both using cotton swab and cryogels for comparison. Paints were characterized using Fourier Transform Infrared spectroscopy (FT-IR), pyrolysis - gas chromatography - mass spectrometry (Py–GC–MS), Thermogravimetric Analysis (TGA) and Atomic Force Microscope (AFM).All the samples showed different reaction to cleaning according to their different composition. This study revealed that those paint films where most surface alterations are observed after cleaning, are not those that suffer greater changes in the binder matrix.Moreover, a set of samples was aged under accelerated conditions (solar radiation under controlled temperature and humidity). The accelerated ageing was carried out under isochronous sampling up to a maximum of 1426 h. This tests revealed certain degradation processes such as chain scission of the binder that coincide with those alterations observed in several mock-ups after application of the cleaning treatment.

Effects of Sublingual Colostrum Application on Oral and Intestinal Flora of Extremely Low Birth Weight Infants.

The aim of this study is to analyze the effects of colostrum application on the establishment of normal flora in the intestinal tracts and oral cavities of extremely low birth weight infants (ELBWI). A prospective cohort study design was adopted following the STROBE guidelines (Supplementary File 1). Colostrum was administered immediately after obtaining maternal breast milk using a special sterile cotton swab. There were no specific treatments for infants who did not receive colostrum. This experiment was completed on day 5 post-birth and the patients were divided into the colostrum and control groups, corresponding to whether or not colostrum was administered. Throat swabs and stool samples were collected on days 1 and 5 post-birth. Using the conventional bacteria cultivation technique, the detection rate of bacteria in 98 cases of meconium at birth was 15.31%. On day 5, the detection rates of Staphylococcus in the colostrum and control groups were 36.54% and 34.78%, with no significant difference between them (P = 0.856), and that of Enterococcus was 26.92% and 13.04%, respectively, with no statistically significant difference (P = 0.089). Likewise, at birth, the detection rate of bacteria in 98 cases of throat swabs was 27.55%. On day 5, the detection rate of Streptococcus in the colostrum and control groups was 78.85% and 50.00%, respectively, recording a statistically significant difference this time (P = 0.003). Colostrum application had limited effects on intestinal flora colonization but contributes to physiological oral flora colonization.

Cotton swabs wrapped with three-dimensional silver nanoflowers as SERS substrates for the determination of food colorant carmine on irregular surfaces.

A lightweight, portable, low-cost, and accessible cotton swab was employed as surface enhanced Raman spectroscopy (SERS) matrix template. The silver nanoflowers were in situ grown on the surface of cotton swabs to form three-dimensional Ag nanoflower@cotton swabs (AgNF@CS) SERS substrate with high-density and multi-level hot spots. The SERS performance of AgNFs@CS substrates with various reaction time was systematically studied. The optimal AgNF-120@CS SERS substrate exhibits superior detection sensitivity of 10-10M for methylene blue, good signal reproducibility, high enhancement factor of 1.4 × 107, and excellent storage stability (over 30days). Moreover, the AgNF-120@CS SERS substrate also exhibits prominent detection sensitivity of 10-8M for food colorant of carmine. Besides, the portable AgNF-120@CS SERS substrate is also capable of detecting food colorant residues on irregular food surfaces.

Analysis of Spectral Characteristics of Cotton Leaves at Bud Stage under Different Nitrogen Application Rates

Soil salinity affects nutrient uptake by cotton. The cotton bud stage is a very important period in the process of cotton planting and directly affects the yield of cotton. The nutritional status of the bud stage directly affects the reflectance spectra of cotton canopy leaves. Therefore, it is of great significance to nondestructively monitor the nutritional status of the cotton bud stage on salinized soil via spectroscopic techniques and perform corresponding management measures to improve cotton yield. In this study, potted plants with different nitrogen application rates were set up to obtain the reflection spectral curves of cotton bud stage leaves, analyze their spectral characteristics under different nitrogen application rates, and establish spectral estimation models of chlorophyll density. The results are as follows: in the continuum removal spectrum of the cotton bud stage, the lowest point of the absorption valley near 500 nm shifted to the shortwave direction with an increasing nitrogen application rate. The mean reflectance between 765 and 880 nm was significantly different between nitrogen-stressed and nitrogen-unstressed cotton. The average reflectance of the near-infrared band, the absorption valley depths near 500 nm and 675 nm, the first derivative of the 710 nm reflectance, and the second derivatives of the 690 nm and 730 nm reflectance increased with increasing nitrogen application and chlorophyll density, and significant correlations were observed with the chlorophyll density. These parameters were modeled using support vector regression (SVR) and artificial neural network (ANN) methods, two commonly used algorithms in the field of machine learning. The determination coefficients of the three chlorophyll samples via the ANN models were 0.92, 0.77, and 0.94 for the modeling set and 0.77, 0.69, and 0.77 for the verification set. The ratio of quartile to root-mean-square error (RPIQ) of the ANN model was greater than 2.2, and the ratio of the standard error of the measured value to the standard error of the predicted (SEL/SEP) was close to 1, indicating that the chlorophyll density estimation models built based on the ANN algorithm had robust prediction ability. Our model could accurately estimate the leaf chlorophyll density in the cotton bud stage.