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1.
Article in English | MEDLINE | ID: mdl-38852704

ABSTRACT

BACKGROUND: Our purpose was to investigate (1) the difference in external rotation range of motion (ROM) limitation between the two recommended subscapularis-splitting techniques (mid-split versus upper 2/3rd -lower 1/3rd split) and (2) the differences in elevation ROM, internal rotation ROM, the functional outcomes and the internal rotation strength between the two techniques in the Latarjet-Walch procedure. MATERIAL AND METHODS: We conducted a prospective cohort study of patients with recurrent shoulder instability treated by the Latarjet-Walch procedure between January 2021 and January 2022. After a priori calculation of sample size, 32 patients were divided into two groups according to the type of intraoperative subscapularis split [upper 2/3rd -lower 1/3rd level split (LS group, n=19) versus mid-level split (MS group, n=13)] performed in the Latarjet-Walch procedure. RESULTS: The final ER1 (external rotation with the arm adducted) deficit (as compared to opposite normal shoulder) was not significantly different between the LS (9° ± 8°) and the MS (10° ± 8°, p=0.8) groups. The final ER2 (external rotation with the elbow abducted @ 90°) deficit was not significantly different between that of the LS (14° ± 12°) and the MS groups (12° ± 9°, p=0.5). Only in the MS group were the final ER1 deficit (p=0.03) and the final ER2 deficits (p=0.05) significantly better (smaller) than the corresponding baseline values. The Rowe scores (p=0.2) and the shoulder subjective value (p=0.7) were not significantly different between the two groups. There were no postoperative subluxations in either group. However, 3 patients tested positive in apprehension testing in the LS group compared to none in the MS group, the difference being statistically insignificant. The internal rotation strength was 95% of the normal, unaffected shoulder in the LS group and 93% of the normal in the MS group (p=0.6). Computed tomography (CT) scan evaluation showed that the transverse diameter index of subscapularis (upper subscapularis diameter / lower subscapularis diameter) was not different in the MS (0.9 ± 0.1) and the LS (0.9 ± 0.1, p=0.3) groups. CONCLUSION: We found no difference in final external rotation limitation between the upper 2/3rd - lower 1/3rd versus mid-level subscapularis split techniques. The functional outcomes, the internal rotation strength, subscapularis transverse diameter index, and fatty infiltration in the CT scan were similar in both groups.

2.
Addit Manuf ; 842024 Mar.
Article in English | MEDLINE | ID: mdl-38567361

ABSTRACT

The working curve informs resin properties and print parameters for stereolithography, digital light processing, and other photopolymer additive manufacturing (PAM) technologies. First demonstrated in 1992, the working curve measurement of cure depth vs radiant exposure of light is now a foundational measurement in the field of PAM. Despite its widespread use in industry and academia, there is no formal method or procedure for performing the working curve measurement, raising questions about the utility of reported working curve parameters. Here, an interlaboratory study (ILS) is described in which 24 individual laboratories performed a working curve measurement on an aliquot from a single batch of PAM resin. The ILS reveals that there is enormous scatter in the working curve data and the key fit parameters derived from it. The measured depth of light penetration Dp varied by as much as 7x between participants, while the critical radiant exposure for gelation Ec varied by as much as 70x. This significant scatter is attributed to a lack of common procedure, variation in light engines, epistemic uncertainties from the Jacobs equation, and the use of measurement tools with insufficient precision. The ILS findings highlight an urgent need for procedural standardization and better hardware characterization in this rapidly growing field.

3.
Crit Rev Anal Chem ; : 1-11, 2023 Sep 06.
Article in English | MEDLINE | ID: mdl-37672314

ABSTRACT

Retention prediction through Artificial intelligence (AI)-based techniques has gained exponential growth due to their abilities to process complex sets of data and ease the crucial task of identification and separation of compounds in most employed chromatographic techniques. Numerous approaches were reported for retention prediction in different chromatographic techniques, and consistent results demonstrated that the accuracy and effectiveness of deep learning models outclassed the linear machine learning models, mainly in liquid and gas chromatography, as ML algorithms use fewer complex data to train and predict information. Support Vector machine-based neural networks were found to be most utilized for the prediction of retention factors of different compounds in thin-layer chromatography. Cheminformatics, chemometrics, and hybrid approaches were also employed for the modeling and were more reliable in retention prediction over conventional models. Quantitative Structure Retention Relationship (QSRR) was also a potential method for predicting retention in different chromatographic techniques and determining the separation method for analytes. These techniques demonstrated the aids of incorporating QSRR with AI-driven techniques acquiring more precise retention predictions. This review aims at recent exploration of different AI-driven approaches employed for retention prediction in different chromatographic techniques, and due to the lack of summarized literature, it also aims at providing a comprehensive literature that will be highly useful for the society of scientists exploring the field of AI in analytical chemistry.

4.
Soft Matter ; 19(37): 7172-7183, 2023 Sep 27.
Article in English | MEDLINE | ID: mdl-37702523

ABSTRACT

Digital light processing (DLP)-based additive manufacturing has emerged as a powerful technique for fabricating structures from filled resin systems, in which the light scattering behavior is critical to the dimensional fidelity of the cured part. Recently created low density filled resins that incorporate hollow microspheres introduce a third optically active phase, producing yet more complex scattering and cure behaviours that existing empirical relationships cannot predict. This study simulates light scattering in these systems via Mie theory and a novel Monte Carlo model, providing insight into the relationship between filler volume fraction and cured dimensions, and proposes an inversion parameter for predicting film dimensions. Cured resin geometry dimensions such as cured depth (CD) and cured width (CW) are predicted using the developed model for 10, 30, and 50 vol% hollow glass microsphere filled resin systems. In contrast to standard two-phase models, our three-phase model predicts a positive relationship between cured depths and half-widths and the filler volume fraction, consistent with experimental data. By elucidating the intricacies of light scattering in three-phase systems, this work provides valuable insights for advancing DLP-based additive manufacturing and designing filled resin formulations to achieve the desired cured dimensions.

5.
Org Biomol Chem ; 21(39): 7917-7923, 2023 Oct 11.
Article in English | MEDLINE | ID: mdl-37642260

ABSTRACT

An interesting molecular architecture, butterflyene, resembling the shape of a butterfly has been synthesized via a sequence of cyclocondensation, benzylic oxidation, McMurry coupling and Diels-Alder reaction (DAR), successively. The DAR of the tetrasubstituted double bond of a bicyclopentylidene moiety with various dienes has been performed to prepare the analogues of butterflyene. DFT calculations have also been used to analyze the structural optimization and reaction energies.

6.
Anal Methods ; 15(23): 2785-2797, 2023 06 15.
Article in English | MEDLINE | ID: mdl-37264667

ABSTRACT

Artificial intelligence (AI) and machine learning (ML) gained tremendous growth and are rapidly becoming popular in various fields of prediction due to their potential abilities, accuracy, and speed. Machine learning algorithms employ historical data to analyze or predict information using patterns or trends. AI and ML were most employed in chromatographic predictions and particularly attractive options for liquid chromatography method development, as they can help achieve desired results faster, more accurately, and more efficiently. This review aims at exploring various AI and ML models employed in the determination of chromatographic characteristics. This review also aims to provide deep insight into reported artificial neural network (ANN) associated techniques which maintained better accuracy and significant possibilities for chromatographic characteristics prediction in liquid chromatography over classical linear models and also emphasizes the integration of a fuzzy system with an ANN, as this integrated study provides more efficient and accurate methods in chromatographic prediction than other linear models. This study also focuses on the retention prediction of a target molecule employing QSRR methodology combined with an ANN, highlighting a more effective technique than the QSRR alone. This approach showed the benefits of combining AI or ML algorithms with the QSRR to obtain more accurate retention predictions, emphasizing the potential of artificial intelligence and machine learning for overcoming adversities in analytical chemistry.


Subject(s)
Artificial Intelligence , Machine Learning , Neural Networks, Computer , Algorithms , Chromatography, Liquid
7.
JSES Int ; 7(2): 230-238, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36911765

ABSTRACT

Background: Although the classic open Latarjet has a low recurrence rate in unstable shoulders, this advantage may be offset by the higher number of complications. We aimed to report the safety-driven nuanced steps and the resulting short-term complications of the Latarjet-Walch technique. Methods: Between 2016 and 2022, 150 patients who underwent the Latarjet procedure following the key safety-driven technical steps were retrospectively evaluated for intraoperative and short-term (3 months) complications. The complications were divided into 3 types: Any adverse event that did not need a change in the treatment protocol was a type 1 complication. An event that resulted in a prolongation of rehabilitation protocol or an additional medical line of treatment was classified as type 2, and an event that resulted in readmission, a resurgery, or one that affected the outcome was classified as a type 3 complication. Results: There were 12 (8%) short-term complications in 9 patients. Neurological complications were noted in 3 (2%) patients (1 axillary nerve injury, 1 suprascapular nerve injury, and 1 musculocutaneous nerve injury). Type 1 complications were noted in 2 patients: 2 patients had hematoma that was detected as superficial swelling, but no surgical drainage was needed, and both resolved at their 1-month follow-up. Type 2 complications were noted in 4 patients. One patient had surgical site infection and a second patient had superficial wound dehiscence in the lower part of the wound. The third patient had suprascapular nerve paresis and the fourth had musculocutaneous nerve paresis and shoulder stiffness. Both nerve injuries recovered completely after 6 months of rehabilitation. Type 3 complications were noted in 3 patients. One patient had axillary nerve paresis and shoulder stiffness. The axillary nerve palsy had recovered partially by 8 months. One patient had an intraoperative graft fracture and postoperative shoulder stiffness, and the third patient had shoulder stiffness. Conclusion: Following the safety-driven nuanced steps in the Latarjet-Walch procedure, the short-term complication rate was 8%, and the neurological complication was 2% (n = 3). The musculocutaneous and suprascapular nerves completely recovered, and the axillary nerve had partially recovered.

8.
J Shoulder Elbow Surg ; 32(3): e94-e105, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36252784

ABSTRACT

BACKGROUND: The primary purpose was to compare coracoid graft resorption after the Latarjet procedure in patients without preoperative glenoid bone loss vs. those with more than critical glenoid loss. The secondary purposes were to compare the functional outcomes and to investigate the association of graft position, angle of the screws, preoperative glenoid defect, age at surgery, and smoking status with graft resorption. METHODS: Sixty consecutive patients with recurrent anterior instability were treated by the Latarjet procedure as the index procedure, irrespective of the glenoid bone loss between 2018 and 2021. Fifty-five patients were evaluated via computed tomography scans after a minimum of 1 year after surgery (range: 1-4 years). Twenty-five patients had no prior glenoid defect (No-defect group), 24 patients had preoperative glenoid defects ≥15% (Critical defect group), and 6 patients had glenoid defects between 5% and 15%. The No-defect group (n = 25) was compared with the Critical defect group (n = 24). Multivariate logistical regression was performed to evaluate the association of independent factors with the grade of resorption for all 55 patients in the cohort. RESULTS: Major graft resorption at the level of the superior screw was observed in 72%-84% of patients in the No-defect group (n = 25) and in 75%-83% of patients in the Critical defect group (n = 24) (P = 1, P = 1; no significant difference). No to mild resorption at the level of the inferior screw was observed in 96% of patients in the No-defect group and 100% of patients in the Critical defect group (P = 1; no significant difference). Postoperative Rowe scores (100 [95-100] vs. 100 [95-100]; P = .8) and shoulder subjective value (87 [11] vs. 86 [9]; P = .9) were not significantly different between the 2 groups. None of the independent factors, including the corresponding screw angle, the mediolateral graft positioning, prior glenoid defect, age, and smoking status, were associated with graft resorption in multivariate logistical regression. CONCLUSIONS: Graft resorption after the Latarjet procedure does not depend on the preoperative glenoid defect. The coracoid graft may be mostly resorbed around the superior screw but mildly or none at the level of the inferior screw, but this graft resorption is not dependent on the smoking status, age, prior glenoid defect, mediolateral graft positioning, and the angle of the screws.


Subject(s)
Joint Instability , Shoulder Dislocation , Shoulder Joint , Humans , Shoulder Joint/diagnostic imaging , Shoulder Joint/surgery , Shoulder Dislocation/diagnostic imaging , Shoulder Dislocation/surgery , Neoplasm Recurrence, Local , Scapula/diagnostic imaging , Scapula/surgery , Arthroplasty , Joint Instability/diagnostic imaging , Joint Instability/surgery
9.
Cureus ; 14(11): e31842, 2022 Nov.
Article in English | MEDLINE | ID: mdl-36579232

ABSTRACT

Objective To investigate the incidence of genital infection due to the use of sodium-glucose cotransporter-2 (SGLT-2) inhibitors in patients with type 2 diabetes mellitus (T2DM) concomitant coronary artery diseases (CAD). Methods A single-center, physician-initiated study was conducted at a tertiary-care center in India. The study enrolled patients with T2DM who were taking SGLT-2 inhibitors for at least two months and divided them into two groups: patients with concomitant CAD as the case group and without CAD as the control group. Demographic data and medical history of patients were documented using a standard questionnaire. Itching and swelling were the signs used for the diagnosis of genital infection. Results A total of 270 consecutive patients with T2DM were enrolled and divided into two groups: 48 patients with CAD as the case group and 222 patients without CAD as the control group. The mean age of patients with CAD was 63.27±7.53 years and without CAD was 58.32±14.89 years. The mean HbA1C levels were 8.40±1.71% in the case group and 8.60±7.20% in the control group. A total of 14.6% of patients with CAD and 12.6% of patients without CAD were found to have genital infections (p=0.712). SGLT-2 inhibitors were stopped in only six patients who had genital infections and all the patients were managed using anti-fungal cream and via maintenance of proper hygiene. The overall incidence of genital infection was about 12.96%, of which only 2.7% required discontinuation of this crucial therapy. Conclusion In conclusion, the incidence of genital infection with the use of SGLT-2 inhibitors is similar among patients with T2DM with concomitant CAD and without CAD. The measures to prevent genital infection should be strongly emphasized. However, larger, well-designed studies are required to validate the current findings.

10.
Sci Rep ; 12(1): 19017, 2022 11 17.
Article in English | MEDLINE | ID: mdl-36396727

ABSTRACT

The building and construction sector accounts for around 39% of global carbon dioxide emissions and remains a hard-to-abate sector. We use a data-driven analysis of global high-level climate action on emissions reduction in the building sector using 256,717 English-language tweets across a 13-year time frame (2009-2021). Using natural language processing and network analysis, we show that public sentiments and emotions on social media are reactive to these climate policy actions. Between 2009-2012, discussions around green building-led emission reduction efforts were highly influential in shaping the online public perceptions of climate action. From 2013 to 2016, communication around low-carbon construction and energy efficiency significantly influenced the online narrative. More significant interactions on net-zero transition, climate tech, circular economy, mass timber housing and climate justice in 2017-2021 shaped the online climate action discourse. We find positive sentiments are more prominent and recurrent and comprise a larger share of the social media conversation. However, we also see a rise in negative sentiment by 30-40% following popular policy events like the IPCC report launches, the Paris Agreement and the EU Green Deal. With greater online engagement and information diffusion, social and environmental justice topics emerge in the online discourse. Continuing such shifts in online climate discourse is pivotal to a more just and people-centric transition in such hard-to-decarbonise sectors.


Subject(s)
Social Media , Humans , Climate , Carbon Dioxide/analysis , Policy , Communication
11.
Polymers (Basel) ; 14(16)2022 Aug 11.
Article in English | MEDLINE | ID: mdl-36015530

ABSTRACT

Shape memory elastomers have revolutionised the world since their introduction in the 20th century. The ability to tailor chemical structures to produce a family of materials in wide-ranging forms with versatile properties has propelled them to be ubiquitous. Recent challenges in the end-of-life management of polymeric materials should prompt us to ask, 'what innovations in polymeric materials can make a strong case for their use as efficient materials?' The development of smart elastomers that can acquire, convey, or process a stimulus (such as temperature, pressure, electromagnetic field, moisture, and chemical signals) and reply by creating a useful effect, specifically a reversible change in shape, is one such innovation. Here, we present a brief overview of shape memory elastomers (SMEs) and thereafter a review of recent advances in their development. We discuss the complex processing of structure-property relations and how they differ for a range of stimuli-responsive SMEs, self-healing SMEs, thermoplastic SMEs, and antibacterial and antifouling SMEs. Following innovations in SEMs, the SMEs are forecast to have significant potential in biotechnology based on their tailorable physical properties that are suited to a range of different external stimuli.

12.
BMC Neurol ; 22(1): 151, 2022 Apr 22.
Article in English | MEDLINE | ID: mdl-35459157

ABSTRACT

BACKGROUND: The Guillain-Barre Syndrome (GBS), also known as acute idiopathic polyneuritis, is a critical acquired condition associated with preceding nonspecific infection or triggering factors like trauma, surgery, or vaccination. GBS is currently the most frequent cause of acute flaccid paralysis in India. This study evaluates the short-term and in-hospital outcomes in different subtypes of GBS. METHODS: A prospective observational study was conducted at V.S. Hospital, Ahmedabad, from September 2015 to December 2017. Patients above the age of 12 were included. Patients having other underlying neurological conditions, as well as immunodeficiency disorders, were excluded. The patients were classified into different subtypes of GBS, and functional outcomes were recorded on admission and discharge according to Hughes Scoring System. All statistical analyses were performed by using SPSS software. RESULTS: Out of 50 patients, 35 (70%) were males. The mean age was of 37.18 +/- 18.35 years. 25 (50%) patients had a preceding infection. 88% of patients presented with cranial nerve (CN) involvement had a Hughes Score of >/= 3 (p = 0.0087). They had less improvement of Hughes Score on discharge (0.13 +/- 0.04) as compared to the patients without cranial nerve involvement (0.38 +/- 0.08) (p = 0.008). Respiratory involvement was associated with a higher Hughes Score (p = 0.005) on admission. 85% of patients diagnosed with an axonal subtype of GBS had a Hughes Score of >/= 3 (p = 0.06) compared to 74% patients with demyelinating subtype. Axonal subtype required double period (11 +/- 2.34) to show improvement as compared to demyelinating subtype (6 +/- 1.2) (p = 0.020). Irrespective of the subtypes, in two different treatment cohorts (PLEX vs IVIG), there was no difference in short term functional outcomes measured by improvement in the Hughes scores (p = 0.89). CONCLUSIONS: Early cranial nerve and respiratory involvement in patients presenting with GBS are associated with poor outcomes warranting immediate critical care involvement. In our study, amongst all the subtypes, axonal had poor clinical outcomes. Further clinical trials on the Indian subpopulation will help us evaluate the impact of different treatment modalities on this disease.


Subject(s)
Guillain-Barre Syndrome , Myelitis , Adolescent , Adult , Axons , Female , Guillain-Barre Syndrome/diagnosis , Guillain-Barre Syndrome/epidemiology , Guillain-Barre Syndrome/therapy , Humans , Male , Middle Aged , Prospective Studies , Tertiary Care Centers , Young Adult
13.
Adv Mater ; 34(23): e2201577, 2022 Jun.
Article in English | MEDLINE | ID: mdl-35365942

ABSTRACT

Insight into fiber formation can provide new rationale for the design and preparation of fibers with programmed mechanical properties. While synthetic bioinspired fibers have shown impressive tensile properties, the fiber formation process remains poorly understood. Moreover, these systems are highly complex and their formation is environmentally and economically costly. Controlled fiber formation under ambient conditions from polyacrylamide solutions with properties comparable to natural fibers such as wool and coir is demonstrated. Photopolymerization and subsequent microscale fibrillation of different acrylamides in water/ethanol mixtures yield a simple and energy-efficient route to fiber formation. This strategy reduces required processing energy by two-to-three orders of magnitude. Through extensive experimental elucidation, insight into precise fiber forming conditions of polymeric solutions is achieved. Ethanol is utilized as a chain transfer agent to control the molecular weight of the polyacrylamides, and the entanglement regimes of the solutions are determined through rheological characterization showing fiber formation above the entanglement concentration. Unique from previously reported hydrogel microfibers, it is shown that fibers with good mechanical properties can be obtained without the need for composites or crosslinkers. The reported approach offers a platform for fiber formation under ambient conditions with molecular-level understanding of their assembly.

14.
J Stroke Cerebrovasc Dis ; 31(4): 106216, 2022 Apr.
Article in English | MEDLINE | ID: mdl-35091266

ABSTRACT

OBJECTIVES: Intracerebral Hemorrhage (ICH) accounts for 10% of strokes annually in the United States (US). Up-to-date trends in disease burden and regional variations remain unknown. Our study reports updated trends of ICH incidence, mortality, and mortality to incidence ratio (MIR) across the US. MATERIALS AND METHODS: Observational study to evaluate the incidence and mortality from ICH across the US. Data was obtained from Global Burden of Disease (GBD) database. Age-Standardized Incidence (ASIRs) and Death (ASDRs) Rates, as well as the Mortality- to-Incidence ratios (MIRs) for ICH in the US overall and state-wise from 1990-2017. Joinpoint regression analysis was used, with presentation of estimated annual percentage changes (EAPCs). RESULTS: Overall decrease in ASIRs, ASDRs, and MIRs in the US for both sexes. The 2017 mean ASIR was 25.67/100,000 for men and 19.17/100,000 for women, whereas mean ASDR was 13.96/100,000 for men and 11.35/100,000 for women. District of Columbia had greatest decreases in ASIR EAPCs for both men and women at -41.25% and -40.58%, respectively, and greatest decreases in ASDR EAPCs for men and women at -55.38% and -48.51%, respectively. MIR between 1990-2017 decreased in men by -12.12% and women by -7.43%. MIR increased in men from 2014-2017 (EAPC +2.2%) and in women from 2011-2017 (EAPC +1.0%). CONCLUSION: Decreasing trends in incidence, mortality, and MIR. No significant trends in mortality were found in the last 6 years of the study period. MIR worsened in males from 2014-2017 and females from 2011-2017, suggesting decreased ICH-related survival lately.


Subject(s)
Global Burden of Disease , Stroke , Cerebral Hemorrhage/diagnosis , Cerebral Hemorrhage/epidemiology , Epidemiologic Studies , Female , Humans , Incidence , Male , Stroke/epidemiology , United States/epidemiology
15.
J Shoulder Elbow Surg ; 31(1): 201-208, 2022 Jan.
Article in English | MEDLINE | ID: mdl-34352402

ABSTRACT

BACKGROUND: Shoulder range-of-motion (ROM) assessment is vital for the follow-up evaluation of operated patients and for the outcome-based research studies. The aim of this study was to investigate the accuracy and reliability of a remote on-screen application (app)-based method of shoulder ROM measurement through a telehealth medium. MATERIALS AND METHODS: A consultant shoulder surgeon, a board-certified orthopedic resident, and a graduate medical doctor served as the examiners. The cohort consisted of 24 healthy volunteers and 16 symptomatic patients with expected shoulder ROM deficits. Shoulder ROM was first examined physically using a goniometer in the clinic and then over Zoom remote conferencing using the protractor extension app of the Chrome browser. RESULTS: Instrument validity was examined by comparing the goniometer method with the protractor app-based method of the expert shoulder consultant using Bland-Altman analysis. It showed only minor mean differences between the healthy volunteers and the patients in elevation (2.0° and 5.0°, respectively), abduction (2.0° and 3.0°, respectively), external rotation with the elbow adducted (1.9° and 0.2°, respectively), external rotation with the elbow abducted at 90° (0.4° and 4°, respectively), and internal rotation with elbow abducted at 90° (2.3° and 1.2°, respectively), with limits of agreement that were below the well-established minimal clinically important difference values. The intraclass correlation coefficient (ICC) values varied between 0.83 and 0.96 for the volunteers and between 0.90 and 0.98 for the patients, indicating excellent correlation between the 2 methods. The interobserver reliability between 2 examiners for the protractor app-based method as evaluated by ICC scores was excellent; it ranged between 0.86 and 0.98 for the volunteers and between 0.88 and 0.99 for the patients. Comparison of the protractor app-based method with the gold-standard goniometer method for the resident and the graduate doctor showed excellent ICC values. CONCLUSION: A protractor app-based method of measuring shoulder ROM over a telehealth medium is accurate and reliable compared with a clinical goniometer method. This validated method can be used during remote telehealth consultation with significant benefits of saving patients travel and time during the COVID-19 (coronavirus disease 2019) pandemic and even later.


Subject(s)
COVID-19 , Telemedicine , Arthrometry, Articular , Humans , Range of Motion, Articular , Reproducibility of Results , SARS-CoV-2 , Shoulder
16.
Nat Plants ; 7(9): 1200-1206, 2021 09.
Article in English | MEDLINE | ID: mdl-34518667

ABSTRACT

Flax has a long and fascinating history. This plant was domesticated around 8,000 BCE1 in the Fertile Crescent area2, first for its seeds and then for its fibres1,3. Although its uses existed long before domestication, residues of flax yarn dated 30,000 years ago have been found in the Caucasus area4. However, Ancient Egypt laid the foundations for the cultivation of flax as a textile fibre crop5. Today flax fibres are used in high-value textiles and in natural actuators6 or reinforcements in composite materials7. Flax is therefore a bridge between ages and civilizations. For several decades, the development of non- or micro-destructive analysis techniques has led to numerous works on the conservation of ancient textiles. Non-destructive methods, such as optical microscopy8 or vibrational techniques9,10, have been largely used to investigate archaeological textiles, principally to evaluate their degradation mechanisms and state of conservation. Vibrational spectroscopy studies can now benefit from synchrotron radiation11 and X-ray diffraction measurement in the archaeometric study of historical textiles12,13. Conservation of mechanical performance and the ultrastructural differences between ancient and modern flax varieties have not been examined thus far. Here we examine the morphological, ultrastructural and mechanical characteristics of a yarn from an Egyptian mortuary linen dating from the early Middle Kingdom (Eleventh Dynasty, ca. 2033-1963 BCE) and compare them with a modern flax yarn to assess the quality and durability of ancient flax fibres and relate these to their processing methods. Advanced microscopy techniques, such as nano-tomography, multiphoton excitation microscopy and atomic force microscopy were used. Our findings reveal the cultural know-how of this ancient civilization in producing high-fineness fibres, as well as the exceptional durability of flax, which is sometimes questioned, demonstrating their potential as reinforcements in high-technology composites.


Subject(s)
Archaeology/history , Flax/chemistry , Flax/ultrastructure , Textiles/history , Egypt , History, Ancient , Microscopy, Electron, Scanning
17.
J Orthop ; 26: 29-35, 2021.
Article in English | MEDLINE | ID: mdl-34290485

ABSTRACT

PURPOSE: Roof arc angle (RAA) is determined by measuring angle between a vertical line drawn from center of the acetabulum towards the acetabular dome and a second line drawn from center of acetabulum to the fracture through the acetabulum. Joel and Matta demonstrated that when roof arc angle was less than 45° on Pelvic AP and Judet's views, the fracture line is considered to be passing through the weight-bearing dome and require surgical fixation. The main purpose of the study is to calculate patient-specific angle and width for the better evaluation and management of acetabular fractures. METHODS: Radiographs of normal hips were retrieved from electronic data and parameters were calculated. Two observers calculated the parameters at two different intervals. Pearson correlation formula was used to find a correlation between groups. RESULTS: Fifty radiographs of 28 patients were reviewed. The mean age of patients was 75.58 years ±13.28. The radius of the acetabulum, the radiographic measurement of sector width for 45° angulation at the roof, and the mathematical calculation for roof arc for 45° angle had significant positive correlation for both observers at two different occasions. CONCLUSIONS: The measured roof arc width ranges from a minimum of 16.20 mm-31.50 mm and the calculated arc width for a 45-degree angle varies from a minimum of 15 mm-25.56 mm. These values are higher than the described values of 10 mm equals to 45 degrees. Hence, the values measured in this study should be considered for decision making in the management of acetabular fractures.

18.
Polymers (Basel) ; 13(14)2021 Jul 06.
Article in English | MEDLINE | ID: mdl-34300983

ABSTRACT

PLA-flax non-woven composites are promising materials, coupling high performance and possible degradation at their end of life. To explore their ageing mechanisms during garden composting, microstructural investigations were carried out through scanning electron microscopy (SEM) and atomic force microscopy (AFM). We observe that flax fibres preferentially degrade 'inwards' from the edge to the core of the composite. In addition, progressive erosion of the cell walls occurs within the fibres themselves, 'outwards' from the central lumen to the periphery primary wall. This preferential degradation is reflected in the decrease in indentation modulus from around 23 GPa for fibres located in the preserved core of the composite to 3-4 GPa for the remaining outer-most cell wall crowns located at the edge of the sample that is in contact with the compost. Ageing of the PLA matrix is less drastic with a relatively stable indentation modulus. Nevertheless, a change in the PLA morphology, a significant decrease in its roughness and increase of porosity, can be observed towards the edge of the sample, in comparison to the core. This work highlights the important role of intrinsic fibre porosity, called lumen, which is suspected to be a major variable of the compost ageing process, providing pathways of entry for moisture and microorganisms that are involved in cell wall degradation.

19.
Int J Spine Surg ; 14(s4): S89-S95, 2021 Feb.
Article in English | MEDLINE | ID: mdl-33900950

ABSTRACT

BACKGROUND: To report 2 different presentations of thoracic myelopathy with ossification of ligamantum flavum (OLF) due to fluorosis. METHODS: Two females presented with thoracic myelopathy secondary to spinal stenosis with OLF due to fluorosis. On examination, the first patient had a grade 4 power in both lower limbs with altered sensation below L1 dermatome. She had segmental OLF on magnetic resonance imaging and computed tomography and was treated with posterior thoracic laminectomy and recovered well. The second patient had a history of a prior thoracic laminectomy at another institution and presented with paraplegia with bladder involvement. Radiological investigations revealed a 3-column injury at the level of D8/D9. This patient was treated with decompression and stabilization. RESULTS: The first patient recovered neurologically and regained independent ambulation while the second patient had a reduction in spasticity but no recovery of power or bladder function. CONCLUSION: Different presentations and causes of myelopathy due to OLF should be recognized and treated. An unstable injury is very rare and should not be missed.

20.
PLoS One ; 16(2): e0245737, 2021.
Article in English | MEDLINE | ID: mdl-33556092

ABSTRACT

The COVID-19 pandemic has created enormous global demand for personal protective equipment (PPE). Face shields are an important component of PPE for front-line workers in the context of the COVID-19 pandemic, providing protection of the face from splashes and sprays of virus-containing fluids. Existing face shield designs and manufacturing procedures may not allow for production and distribution of face shields in sufficient volume to meet global demand, particularly in Low and Middle-Income countries. This paper presents a simple, fast, and cost-effective curved-crease origami technique for transforming flat sheets of flexible plastic material into face shields for infection control. It is further shown that the design could be produced using a variety of manufacturing methods, ranging from manual techniques to high-volume die-cutting and creasing. This demonstrates the potential for the design to be applied in a variety of contexts depending on available materials, manufacturing capabilities and labour. An easily implemented and flexible physical-digital parametric design methodology for rapidly exploring and refining variations on the design is presented, potentially allowing others to adapt the design to accommodate a wide range of ergonomic and protection requirements.


Subject(s)
COVID-19/prevention & control , Personal Protective Equipment , COVID-19/virology , Humans , Imaging, Three-Dimensional , Photogrammetry , SARS-CoV-2/physiology
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