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1.
Nanoscale ; 15(45): 18500-18510, 2023 Nov 23.
Article in English | MEDLINE | ID: mdl-37942933

ABSTRACT

The direct integration of 1D magnetic nanostructures into electronic circuits is crucial for realizing their great potential as components in magnetic storage, logical devices, and spintronic applications. Here, we present a novel template-free technique for producing magnetic nanochains and nanowires using directed self-assembly of gas-phase-generated metallic nanoparticles. The 1D nanostructures can be self-assembled along most substrate surfaces and can be freely suspended over micrometer distances, allowing for direct incorporation into different device architectures. The latter is demonstrated by a one-step integration of nanochains onto a pre-patterned Si chip and the fabrication of devices exhibiting magnetoresistance. Moreover, fusing the nanochains into nanowires by post-annealing significantly enhances the magnetic properties, with a 35% increase in the coercivity. Using magnetometry, X-ray microscopy, and micromagnetic simulations, we demonstrate how variations in the orientation of the magnetocrystalline anisotropy and the presence of larger multi-domain particles along the nanochains play a key role in the domain formation and magnetization reversal. Furthermore, it is shown that the increased coercivity in the nanowires can be attributed to the formation of a uniform magnetocrystalline anisotropy along the wires and the onset of exchange interactions.

2.
Analyst ; 148(17): 4002-4011, 2023 Aug 21.
Article in English | MEDLINE | ID: mdl-37482759

ABSTRACT

Electronic cigarettes are a popular nicotine consumption product that have risen in popularity as an alternative to cigarettes. However, their recent meteoric rise in market size and various controversies have resulted in the analyses of e-liquid ingredients to be focused on powerful laboratory-based slow methods such as chromatography and mass spectrometry. Here we present a complementary technology based on Raman spectroscopy combined with chemometrics as a fast, inexpensive, and highly portable screening tool to detect and quantify the propylene glycol : glycerol (PG : VG) ratio and nicotine content of e-cigarette liquids. Through this, the PG : VG ratio of 20 out of 23 commercial samples was quantified to within 3% of their stated value, while nicotine was successfully quantified to within 1 mg g-1 for 16 out of 23 samples without the need for accurate knowledge of flavonoid composition. High linearity was also achieved when flavours were kept constant. Finally, the limitations of Raman spectroscopy are discussed, and potential solutions are suggested.


Subject(s)
Electronic Nicotine Delivery Systems , Nicotine , Nicotine/analysis , Spectrum Analysis, Raman , Propylene Glycol/chemistry , Glycerol
3.
Biology (Basel) ; 12(7)2023 Jul 05.
Article in English | MEDLINE | ID: mdl-37508393

ABSTRACT

In cancer development and its clinical course, bacteria can be involved in etiology and secondary infection. Regarding etiology, various epidemiological studies have revealed that Helicobacter pylori can directly impact gastric carcinogenesis. The Helicobacter pylori-associated virulence factor cytotoxin-associated gene A perhaps plays an important role through different mechanisms such as aberrant DNA methylation, activation of nuclear factor kappa B, and modulation of the Wnt/ß-catenin signaling pathway. Many other bacteria, including Salmonella and Pseudomonas, can also affect Wnt/ß-catenin signaling. Although Helicobacter pylori is involved in both gastric adenocarcinoma and mucosa-associated lymphoid tissue lymphoma, its role in the latter disease is more complicated. Among other bacterial species, Chlamydia is linked with a diverse range of diseases including cancers of different sites. The cellular organizations of Chlamydia are highly complex. Interestingly, Escherichia coli is believed to be associated with colon cancer development. Microorganisms such as Escherichia coli and Pseudomonas aeruginosa are frequently isolated from secondary infections in cancer patients. In these patients, the common sites of infection are the respiratory, gastrointestinal, and urinary tracts. There is an alarming rise in infections with multidrug-resistant bacteria and the scarcity of suitable antimicrobial agents adversely influences prognosis. Therefore, effective implementation of antimicrobial stewardship strategies is important in cancer patients.

4.
Int J Mol Sci ; 24(6)2023 Mar 10.
Article in English | MEDLINE | ID: mdl-36982392

ABSTRACT

Multi-drug resistant bacterial strains (MDR) have become an increasing challenge to our health system, resulting in multiple classical antibiotics being clinically inactive today. As the de-novo development of effective antibiotics is a very costly and time-consuming process, alternative strategies such as the screening of natural and synthetic compound libraries is a simple approach towards finding new lead compounds. We thus report on the antimicrobial evaluation of a small collection of fourteen drug-like compounds featuring indazoles, pyrazoles and pyrazolines as key heterocyclic moieties whose synthesis was achieved in continuous flow mode. It was found that several compounds possessed significant antibacterial potency against clinical and MDR strains of the Staphylococcus and Enterococcus genera, with the lead compound (9) reaching MIC values of 4 µg/mL on those species. In addition, time killing experiments performed on compound 9 on Staphylococcus aureus MDR strains highlight its activity as bacteriostatic. Additional evaluations regarding the physiochemical and pharmacokinetic properties of the most active compounds are reported and showcased, promising drug-likeness, which warrants further explorations of the newly identified antimicrobial lead compound.


Subject(s)
Anti-Infective Agents , Pyrazoles , Pyrazoles/pharmacology , Pyrazoles/chemistry , Indazoles/pharmacology , Structure-Activity Relationship , Anti-Infective Agents/pharmacology , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Microbial Sensitivity Tests
5.
J Strength Cond Res ; 37(8): 1623-1627, 2023 Aug 01.
Article in English | MEDLINE | ID: mdl-36752757

ABSTRACT

ABSTRACT: Burke, AA, Guthrie, BM, Magee, M, Miller, AD, and Jones, MT. Revisiting the assessment of strength, power, and change of direction in collegiate american football athletes. J Strength Cond Res 37(8): 1623-1627, 2023-The primary purpose was to assess the effect of strength on vertical jump (VJ) and change of direction (COD) with a secondary purpose to examine if these relationships were moderated by the sport position group through path analysis using structural equation modeling. Subjects were collegiate American football athletes grouped by skill (SK; n = 98) and nonskill (NS; n = 83) sport position groups. Maximal strength was assessed by 1 repetition maximum back squat and hang clean (HC). Vertical jump was used to evaluate power. Change of direction was assessed through the 20-yard shuttle (i.e., 5-10-5) test. Multigroup path analysis examined causal pathways among variables and moderating effects of sport position. The final model revealed that VJ fully mediated the relationship between HC and COD (HC-VJ: ß = 0.408, p < 0.001; VJ-COD: ß = -0.376, p < 0.001; and HC-COD: ß = -0.137, p = 0.17) in SK. The NS showed only direct effects of HC on COD ( ß = -0.335, p < 0.001). These findings suggest that strength does not solely explain COD ability but also can serve to enhance underpinning qualities, such as relative force production in the VJ. Relationships between strength, power, and COD are different depending on the positional group. The results provide further insight into performance outcomes in field tests. It is recommended that sport position differences be considered when assessing and analyzing physical qualities in a team setting within the sport of American football.


Subject(s)
Athletic Performance , Football , Humans , Exercise Test , Athletes , Muscle Strength
6.
Appl Ergon ; 106: 103893, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36152447

ABSTRACT

Load carriage (LC) is a contributing factor to musculoskeletal injury in many occupations. Given that falls are a common mechanism of injury for those frequently engaging in LC, understanding the effects of LC on postural stability (PS) is necessary. A systematic review and meta-analysis was conducted to examine effects of LC on PS. Sixteen and 9 studies were included in the qualitative and quantitative synthesis, respectively. In most studies, it was found that LC leads to a decrease in PS with significant effects on center of pressure (COP) sway area (standardized mean difference = 0.45; p < 0.005) and COP anterior-posterior excursion (standardized mean difference = 0.52; p < 0.05). Furthermore, load magnitude and load placement are factors which can significantly affect COP measures of PS. It is recommended to minimize load magnitude and equally distribute load when possible to minimize LC effects on PS. Future research should examine additional factors contributing to differences in individual PS responses to LC such as changes in muscle activation and prior LC experience.


Subject(s)
Musculoskeletal Diseases , Postural Balance , Humans , Young Adult , Postural Balance/physiology , Musculoskeletal Diseases/etiology , Health Status
7.
Metabolites ; 12(11)2022 Nov 04.
Article in English | MEDLINE | ID: mdl-36355152

ABSTRACT

Given the long-term advantages of exclusive breastfeeding to infants and their mothers, there is both an individual and public health benefit to its promotion and support. Data on the composition of human milk over the course of a full period of lactation for a single nursling is sparse, but data on human milk composition during tandem feeding (feeding children of different ages from different pregnancies) is almost entirely absent. This leaves an important knowledge gap that potentially endangers the ability of parents to make a fully informed choice on infant feeding. We compared the metataxonomic and metabolite fingerprints of human milk samples from 15 tandem feeding dyads to that collected from ten exclusively breastfeeding single nursling dyads where the nursling is under six months of age. Uniquely, our cohort also included three tandem feeding nursling dyads where each child showed a preferential side for feeding-allowing a direct comparison between human milk compositions for different aged nurslings. Across our analysis of volume, total fat, estimation of total microbial load, metabolite fingerprinting, and metataxonomics, we showed no statistically significant differences between tandem feeding and single nursling dyads. This included comparisons of preferential side nurslings of different ages. Together, our findings support the practice of tandem feeding of nurslings, even when feeding an infant under six months.

8.
J Educ Health Promot ; 11: 187, 2022.
Article in English | MEDLINE | ID: mdl-36003241

ABSTRACT

BACKGROUND: Cancer is one of the leading causes of death globally. A considerable number of different cancer types may be preventable, using primary intervention techniques, such as health education, cancer awareness, behaviors and lifestyle modifications. The present study conducted a comparative assessment of cancer awareness among undergraduate students of the United States and India. MATERIALS AND METHODS: Students from an Institution in India (KC) (55 females, 33 males), and an Institution in the United States of America (SHU) (226 female, 58 male) during 2019-2020 participated in this study. Participants (n = 372) across all majors and all years (first through fourth year) completed an online questionnaire and answered the questions on their demographic characteristics (e.g., gender, age, and location), academic status (e.g., year of study, major), multiple-choice questions about cancer knowledge, and opinion questions (e.g., "where would you find info," "should therapies be free"). Student responses were collected using Qualtrics Survey Software. Excel was used to analyze responses. We conducted statistical Χ2 tests for independence to determine whether there is a statistically significant difference between the expected frequencies and the observed frequencies in one or more categories of a contingency table, with a significance of ɑ = 0.01. While small sizes due to the small institutions and the response pool, we note that we achieved the necessary "n" for all tests reported. RESULTS: Our research shows a few important statistically significant differences, including knowledge of cancer and breast lumps is dependent on location, ranking of global cancer deaths is dependent on location, and that cancer knowledge is dependent on the information source. All for Χ2 tests with P < 0.001. CONCLUSIONS: Further encouragement of education for young people in various aspects of cancer and cancer prevention, as well as information facility and sources of reliable data, could be helpful for improving the overall health and primary prevention. A thorough assessment is needed to understand the responsible factors for the observed cancer knowledge variations among students of two different places.

9.
Work ; 73(4): 1167-1174, 2022.
Article in English | MEDLINE | ID: mdl-35988244

ABSTRACT

BACKGROUND: Law enforcement recruits (LER) often encounter shoulder injuries, which may cause attrition from academies. Investigating required upper body muscular fitness may inform of muscular balance around shoulder joints through anterior and posterior ratios in LER. OBJECTIVE: To investigate push to pull ratios (P2P) and factors related with P2P in LER. METHODS: LER (95 males; 12 females) completed testing during a single session in the academy's first week: body mass, one-repetition maximum (1RM) bench press, push-up repetitions (reps) to failure, and pull-up reps to failure. Calculations were: estimated pull-up 1RM=body mass+0.033*(body mass x pull-ups); endurance P2P (eP2P)=push-ups / pull-ups; strength P2P (sP2P)=bench press 1RM / estimated pull-up 1RM. Pearson correlation coefficients assessed relationships among tests and P2P (p < 0.05). RESULTS: The sP2P was positively correlated with bench press 1RM and push-ups. The eP2P was negatively associated with pull-up reps and 1RM. Females had similar eP2P, but lower sP2P than male recruits (p < 0.05). CONCLUSION: Practitioners may benefit from examining eP2P and sP2P as they should not be used interchangeably. Future research should examine whether the P2P ratios are associated with injury and subsequent inability to successfully complete law enforcement training academies.


Subject(s)
Muscle Strength , Physical Endurance , Female , Male , Humans , Police , Exercise Test , Exercise , Law Enforcement
10.
ACS Appl Energy Mater ; 5(6): 7728-7734, 2022 Jun 27.
Article in English | MEDLINE | ID: mdl-35783345

ABSTRACT

Using the excess energy of charge carriers excited above the band edge (hot carriers) could pave the way for optoelectronic devices, such as photovoltaics exceeding the Shockley-Queisser limit or ultrafast photodetectors. Semiconducting nanowires show promise as a platform for hot-carrier extraction. Proof of principle photovoltaic devices have already been realized based on InAs nanowires, using epitaxially defined InP segments as energy filters that selectively transmit hot electrons. However, it is not yet fully understood how charge-carrier separation, relaxation, and recombination depend on device design and on the location of optical excitation. Here, we introduce the use of an optical-beam-induced current (OBIC) characterization method, employing a laser beam focused close to the diffraction limit and a high precision piezo stage, to study the optoelectric performance of the nanowire device as a function of the position of excitation. The photocurrent response agrees well with modeling based on hot-electron extraction across the InP segment via diffusion. We demonstrate that the device is capable of producing power and estimate the spatial region within which significant hot-electron extraction can take place to be on the order of 300 nm away from the barrier. When comparing to other experiments on similar nanowires, we find good qualitative agreement, confirming the interpretation of the device function, while the extracted diffusion length of hot electrons varies. Careful control of the excitation and device parameters will be important to reach the potentially high device performance theoretically available in these systems.

11.
J Am Soc Mass Spectrom ; 32(6): 1393-1401, 2021 Jun 02.
Article in English | MEDLINE | ID: mdl-33980015

ABSTRACT

Mass spectrometry has established itself as a powerful tool in the chemical, biological, medical, environmental, and agricultural fields. However, experimental approaches and potential application areas have been limited by a traditional reliance on sample preparation, extraction, and chromatographic separation. Ambient ionization mass spectrometry methods have addressed this challenge but are still somewhat restricted in requirements for sample manipulation to make it suitable for analysis. These limitations are particularly restrictive in view of the move toward high-throughput and automated analytical workflows. To address this, we present what we consider to be the first automated sample-preparation-free mass spectrometry platform utilizing a carbon dioxide (CO2) laser for sample thermal desorption linked to the rapid evaporative ionization mass spectrometry (LA-REIMS) methodology. We show that the pulsatile operation of the CO2 laser is the primary factor in achieving high signal-to-noise ratios. We further show that the LA-REIMS automated platform is suited to the analysis of three diverse biological materials within different application areas. First, clinical microbiology isolates were classified to species level with an accuracy of 97.2%, the highest accuracy reported in current literature. Second, fecal samples from a type 2 diabetes mellitus cohort were analyzed with LA-REIMS, which allowed tentative identification of biomarkers which are potentially associated with disease pathogenesis and a disease classification accuracy of 94%. Finally, we showed the ability of the LA-REIMS system to detect instances of adulteration of cooking oil and determine the geographical area of production of three protected olive oil products with 100% classification accuracy.


Subject(s)
Food Contamination/analysis , Mass Spectrometry/methods , Microbiological Techniques/methods , Specimen Handling/instrumentation , Specimen Handling/methods , Biomarkers/analysis , Case-Control Studies , Diabetes Mellitus, Type 2/metabolism , Equipment Design , Feces , Fiber Optic Technology , Food Analysis/methods , Humans , Lasers , Metabolomics/methods , Olive Oil/analysis
12.
Nano Lett ; 21(2): 988-994, 2021 Jan 27.
Article in English | MEDLINE | ID: mdl-33459021

ABSTRACT

Studies of thermally induced transport in nanostructures provide access to an exciting regime where fluctuations are relevant, enabling the investigation of fundamental thermodynamic concepts and the realization of thermal energy harvesters. We study a serial double quantum dot formed in an InAs/InP nanowire coupled to two electron reservoirs. By means of a specially designed local metallic joule-heater, the temperature of the phonon bath in the vicinity of the double quantum dot can be enhanced. This results in phonon-assisted transport, enabling the conversion of local heat into electrical power in a nanosized heat engine. Simultaneously, the electron temperatures of the reservoirs are affected, resulting in conventional thermoelectric transport. By detailed modeling and experimentally tuning the interdot coupling, we disentangle both effects. Furthermore, we show that phonon-assisted transport is sensitive to excited states. Our findings demonstrate the versatility of our design to study fluctuations and fundamental nanothermodynamics.

13.
Article in English | MEDLINE | ID: mdl-33345040

ABSTRACT

Photobiomodulation therapy (PBMT) can be applied to the whole body as compared to the application of using single hand-held devices that isolate a smaller muscle area. The purpose of this study was to examine the effects of an acute dose of whole-body PBMT pre- and post-high-intensity resistance training on creatine kinase (CK) and salivary interleukin-6 (IL-6) in a sample of trained males. Twelve males (31 ± 8.3 years, 177.2 ± 5.4 cm, and 86.0 ± 7.5 kg) were part of a randomized, counterbalanced, cross-over design, whereby each participant performed a high-intensity resistance training session that consisted of the bench press, chin-up, and repeated sprints on two separate occasions. Each participant was assigned to either the PBMT or control condition on two separate weeks, with a 10-days washout period between the weeks. Creatine kinase was measured at baseline, 24, 48, and 72 h post-exercise. Salivary IL-6 was measured at baseline, 60, 90, and 120 min. A paired t-test showed no significant difference (p = 0.669) in the area under the curve (AUC) for CK during the PBMT (191.7 ± 48.3) and control conditions (200.2 ± 68.0). A Wilcoxon signed-rank test also showed no significant median difference (p = 0.155) in the AUC for salivary IL-6 during the PBMT (Mdn = 347.7) and control conditions (Mdn = 305.8). An additional Wilcoxon signed-rank test for CK percentage change from 24 to 72 h showed the PBMT condition (Mdn = -45%) to have a -18% median difference as compared to the control condition (Mdn = -41%). As such, whole-body PBMT does not significantly reduce the activity of salivary IL-6 or CK concentration during the 24 to 72-h recovery post-high-intensity resistance training.

14.
Asian Pac Isl Nurs J ; 5(3): 139-152, 2020.
Article in English | MEDLINE | ID: mdl-33324731

ABSTRACT

Efforts to improve women's health and to reduce maternal mortality worldwide have led to a notable reduction in the global maternal mortality ratio (MMR) over the past two decades. However, it is clear that maternal health outcomes are not equitable, especially when analyzing the scope of maternal health disparities across "developed" and "underdeveloped" nations. This study evaluates recent MMR scholarship with a particular focus on the racial and ethnic divisions that impact on maternal health outcomes. The study contributes to MMR research by analyzing the racial and ethnic disparities that exist in the US, especially among Asian and Pacific Islander (API) subgroups. The study applies exclusionary criteria to 710 articles and subsequently identified various maternal health issues that disproportionately affect API women living in the US. In applying PRISMA review guidelines, the study produced 22 peer-reviewed articles that met inclusionary and exclusionary criteria for this review. The data analysis identified several maternal health foci: obstetric outcomes, environmental exposure, obstetric care and quality measures, and pregnancy-related measures. Only eight of the 22 reviewed studies disaggregated API populations by focusing on specific subgroups of APIs, which signals a need to reconceptualize marginalized API communities' inclusion in health care systems, to promote their equitable access to care, and to dissolve health disparities among racial and ethnic divides. Several short- and long-term initiatives are recommended to develop and implement targeted health interventions for API groups, and thus provide the groundwork for future empirically driven research among specific API subgroups in the US.

15.
Nutrients ; 12(11)2020 Nov 11.
Article in English | MEDLINE | ID: mdl-33187120

ABSTRACT

Sparse data exist regarding the normal range of composition of maternal milk beyond the first postnatal weeks. This single timepoint, observational study in collaboration with the 'Parenting Science Gang' citizen science group evaluated the metabolite and bacterial composition of human milk from 62 participants (infants aged 3-48 months), nearly 3 years longer than previous studies. We utilised rapid evaporative ionisation mass spectrometry (REIMS) for metabolic fingerprinting and 16S rRNA gene metataxonomics for microbiome composition analysis. Milk expression volumes were significantly lower beyond 24 months of lactation, but there were no corresponding changes in bacterial load, composition, or whole-scale metabolomic fingerprint. Some individual metabolite features (~14%) showed altered abundances in nursling age groups above 24 months. Neither milk expression method nor nursling sex affected metabolite and metataxonomic fingerprints. Self-reported lifestyle factors, including diet and physical traits, had minimal impact on metabolite and metataxonomic fingerprints. Our findings suggest remarkable consistency in human milk composition over natural-term lactation. The results add to previous studies suggesting that milk donation can continue up to 24 months postnatally. Future longitudinal studies will confirm the inter-individual and temporal nature of compositional variations and the use of donor milk as a personalised therapeutic.


Subject(s)
Bacteria/growth & development , Metabolomics/methods , Microbiota , Milk, Human/microbiology , Mothers/statistics & numerical data , Adult , Bacteriological Techniques , Breast Feeding , Female , Humans , Lactation , RNA, Ribosomal, 16S
16.
Nanotechnology ; 31(39): 394004, 2020 Sep 25.
Article in English | MEDLINE | ID: mdl-32526708

ABSTRACT

The separation of hot carriers in semiconductors is of interest for applications such as thermovoltaic photodetection and third-generation photovoltaics. Semiconductor nanowires offer several potential advantages for effective hot-carrier separation such as: a high degree of control and flexibility in heterostructure-based band engineering, increased hot-carrier temperatures compared to bulk, and a geometry well suited for local control of light absorption. Indeed, InAs nanowires with a short InP energy barrier have been observed to produce electric power under global illumination, with an open-circuit voltage exceeding the Shockley-Queisser limit. To understand this behaviour in more detail, it is necessary to establish control over the precise location of electron-hole pair-generation in the nanowire. In this work we perform electron-beam induced current measurements with high spatial resolution, and demonstrate the role of the InP barrier in extracting energetic electrons.We interprete the results in terms of hot-carrier separation, and extract estimates of the hot carriers' mean free path.

17.
Nano Lett ; 20(6): 4064-4072, 2020 Jun 10.
Article in English | MEDLINE | ID: mdl-32347731

ABSTRACT

Nanowires bring new possibilities to the field of hot-carrier photovoltaics by providing flexibility in combining materials for band engineering and using nanophotonic effects to control light absorption. Previously, an open-circuit voltage beyond the Shockley-Queisser limit was demonstrated in hot-carrier devices based on InAs-InP-InAs nanowire heterostructures. However, in these first experiments, the location of light absorption, and therefore the precise mechanism of hot-carrier extraction, was uncontrolled. In this Letter, we combine plasmonic nanoantennas with InAs-InP-InAs nanowire devices to enhance light absorption within a subwavelength region near an InP energy barrier that serves as an energy filter. From photon-energy- and irradiance-dependent photocurrent and photovoltage measurements, we find that photocurrent generation is dominated by internal photoemission of nonthermalized hot electrons when the photoexcited electron energy is above the barrier and by photothermionic emission when the energy is below the barrier. We estimate that an internal quantum efficiency up to 0.5-1.2% is achieved. Insights from this study provide guidelines to improve internal quantum efficiencies based on nanowire heterostructures.

18.
Int J Exerc Sci ; 13(4): 1605-1614, 2020.
Article in English | MEDLINE | ID: mdl-33414875

ABSTRACT

Shoulder joint injuries are common for professional firefighters. A potential cause of shoulder injury is an imbalance between anterior (push) and posterior (pull) shoulder joint musculature. Understanding what contributes to these imbalances may help to identify areas needing improvement. The purpose of this study was to investigate different push to pull (P2P) ratios and the relationships among common upper body fitness assessments, body composition, and push to pull (P2P) ratios in firefighters. Thirty-three professional firefighters completed the following testing protocol: one-repetition maximum (1RM) bench press, pull-up repetitions to failure, push-up repetitions to failure, and a body composition assessment. The endurance P2P (eP2P) was computed by dividing the number of push-up by pull-up repetitions, while strength P2P (sP2P) was the relative 1RM divided by pull-up repetitions. Bivariate relationships among variables were assessed with correlation coefficients and linear regression assessed association between eP2P and sP2P (p ≤ 0.05). The sP2P and eP2P were not associated (R 2 = 0.032, p = 0.99). Strength P2P was related with bench press 1RM (r = 0.80) and push-ups (r = 0.40). Endurance P2P was related with pull-up repetitions (r = -0.62), body fat percentage (r = 0.40), and fat mass index (r = 0.34). The results of the present study suggest sP2P and eP2P ratios should not be used interchangeably. To improve sP2P and eP2P for firefighters, it is recommended to improve the strength of anterior and posterior upper body musculature, respectively, and reduce total body fat mass.

19.
Anal Chem ; 91(21): 13448-13457, 2019 11 05.
Article in English | MEDLINE | ID: mdl-31584799

ABSTRACT

Mass spectrometry is a powerful tool in the investigation of the human fecal metabolome. However, current approaches require time-consuming sample preparation, chromatographic separations, and consequently long analytical run times. Rapid evaporative ionization mass spectrometry (REIMS) is a method of ambient ionization mass spectrometry and has been utilized in the metabolic profiling of a diverse range of biological materials, including human tissue, cell culture lines, and microorganisms. Here, we describe the use of an automated, high-throughput REIMS robotic platform for direct analysis of human feces. Through the analysis of fecal samples from five healthy male participants, REIMS analytical parameters were optimized and used to assess the chemical information obtainable using REIMS. Within the fecal samples analyzed, bile acids, including primary, secondary, and conjugate species, were identified, and phospholipids of possible bacterial origin were detected. In addition, the effect of storage conditions and consecutive freeze/thaw cycles was determined. Within the REIMS mass spectra, the lower molecular weight metabolites, such as fatty acids, were shown to be significantly affected by storage conditions for prolonged periods at temperatures above -80 °C and consecutive freeze/thaw cycles. However, the complex lipid region was shown to be unaffected by these conditions. A further cohort of 50 fecal samples, collected from patients undergoing bariatric surgery, were analyzed using the optimized REIMS parameters and the complex lipid region mass spectra used for multivariate modeling. This analysis showed a predicted separation between pre- and post-surgery specimens, suggesting that REIMS analysis can detect biological differences, such as microbiome-level differences, which have traditionally been reliant upon methods utilizing extensive sample preparations and chromatographic separations and/or DNA sequencing.


Subject(s)
Feces/chemistry , Mass Spectrometry/methods , Metabolomics/methods , Humans
20.
Sci Rep ; 9(1): 3006, 2019 02 28.
Article in English | MEDLINE | ID: mdl-30816263

ABSTRACT

The accurate and timely identification of the causative organism of infection is important in ensuring the optimum treatment regimen is prescribed for a patient. Rapid evaporative ionisation mass spectrometry (REIMS), using electrical diathermy for the thermal disruption of a sample, has been shown to provide fast and accurate identification of microorganisms directly from culture. However, this method requires contact to be made between the REIMS probe and microbial biomass; resulting in the necessity to clean or replace the probes between analyses. Here, optimisation and utilisation of ambient laser desorption ionisation (ALDI) for improved speciation accuracy and analytical throughput is shown. Optimisation was completed on 15 isolates of Escherichia coli, showing 5 W in pulsatile mode produced the highest signal-to-noise ratio. These parameters were used in the analysis of 150 clinical isolates from ten microbial species, resulting in a speciation accuracy of 99.4% - higher than all previously reported REIMS modalities. Comparison of spectral data showed high levels of similarity between previously published electrical diathermy REIMS data. ALDI does not require contact to be made with the sample during analysis, meaning analytical throughput can be substantially improved, and further, increases the range of sample types which can be analysed in potential direct-from-sample pathogen detection.


Subject(s)
Escherichia coli Infections/microbiology , Escherichia coli/chemistry , Lipids/analysis , Molecular Diagnostic Techniques/methods , Spectrometry, Mass, Electrospray Ionization/methods , Escherichia coli/classification , Escherichia coli/pathogenicity , Escherichia coli Infections/diagnosis , Humans , Lasers , Molecular Diagnostic Techniques/instrumentation , Molecular Diagnostic Techniques/standards , Sensitivity and Specificity , Spectrometry, Mass, Electrospray Ionization/instrumentation , Spectrometry, Mass, Electrospray Ionization/standards
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