New insight into the global record of the Ediacaran tubular morphotype: a common solution to early multicellularity

The tubular morphogroup is a common component of Earth's first complex, multicellular communities-the Ediacaran biota-and offers valuable insight into biological traits that are fundamental to animal life because they have intriguing links to metazoan phyla and are highly abundant in Ediacaran ecosystems. Biomineral tubes (e.g. Cloudina) are well described from the Nama assemblage (~550-538 Myr), yielding a relatively detailed understanding of this subset of the morphogroup. Conversely, the non-biomineral tubular taxa of the Nama assemblage, as well as of the older White Sea assemblage (~560-550 Myr), are poorly understood. As a result, the variability of characters that define non-biomineral tubular organisms is unknown and their diversity dynamics throughout the terminal Ediacaran are unconstrained. To test hypotheses related to the diversity, morphological variability and temporal distribution of non-biomineral tubes, a comprehensive database of non-biomineral Ediacaran tubular taxa was compiled. Results demonstrate previously unrecognized morphological disparity in the non-biomineral tubular morphogroup and reveal that it comprises a higher number of genera than all other non-tubular morphogroups in the White Sea and the Nama. Thus, it illustrates that a tubular form dominated Ediacaran ecosystems for considerably longer than previously appreciated and, importantly, was the most common solution to early multicellularity.

Validation of image interpretation for direct vision-guided feeding tube placement

BACKGROUND

Unguided (blind) tube placement commonly results in lung (1.6%) and oesophageal (5%) misplacement, which can lead to pneumothorax, aspiration pneumonia, death, feeding delays, and increased cost. Use of real-time direct vision may reduce risk. We validated the accuracy of a guide to train new operators in the use of direct vision-guided tube placement.

METHODS

Using direct vision, operators matched anatomy viewed to anatomical markers in a preliminary operator guide. We examined how accurately the guide predicted tube position, specifically whether respiratory and gastrointestinal placement could be differentiated.

RESULTS

A total of 100 patients each had one tube placement. Placement was aborted in 6% because of inability to enter or move beyond the oesophagus. In 15 of 20 placements in which the glottic opening was identified, the tube was maneuvered to avoid entry into the respiratory tract. Of 96 tubes that reached the oesophagus, 17 had entered the trachea; all were withdrawn pre-carina. One or more specific characteristics identified each organ, differentiating the trachea-oesophagus (P < 0.0001), oesophagus-stomach, and stomach-intestine in 100%. End-of-procedure tube position was ascertained by pH ≤4.0 (gastric) of aspirated fluid and/or x-ray (gastric or intestinal). In patients with a trauma risk (13%), it was avoided by identification that the tube remained within the nasal, oesophageal, or gastric lumen.

CONCLUSION

Operators successfully matched anatomy seen by direct vision to images and descriptions of anatomy in the "operator guide." This validated that the operator guide accurately facilitates interpretation of tube position and enabled avoidance of lung trauma and oesophageal misplacement.

A Percutaneous Endoscopic Colostomy Tube to the Rescue

Percutaneous endoscopic colostomy (PEC) tube placement is a minimally invasive procedure used to treat recurrent colonic pseudo-obstruction, sigmoid volvulus, chronic intractable constipation, and neurogenic bowel. PEC is a viable treatment alternative for patients who have failed conservative therapies and are deemed high risk for surgical management. We present a case of acute colonic pseudo-obstruction after Clostridioides difficile infection that was unresponsive to medical treatment or endoscopic decompression. A PEC tube was placed into the transverse colon with successful resolution of the colonic distension.

Association between successful weaning from nasogastric tube feeding and thoracic muscle mass in patients with aspiration pneumonia

Nasogastric tube feeding is often used to provide optimal nutrition and hydration in patients with aspiration pneumonia. However, evidence regarding radiologic indicators for successful nasogastric tube weaning is lacking. We investigated whether thoracic skeletal muscle assessment can be useful for predicting successful weaning from nasogastric tube feeding in patients with aspiration pneumonia. This longitudinal, observational study included subjects with aspiration pneumonia who underwent a videofluoroscopic swallowing study (VFSS) and chest computed tomography (CT) in Boramae Medical Center, from January 2012 to December 2019. We estimated the area under the receiver operating characteristics curve (AUC) to evaluate the predictive performance of skeletal muscle and visceral fat parameters and VFSS results for successful weaning from nasogastric tube feeding. A board-certified radiologist measured muscle and fat areas. Muscle and fat volumes were segmented and measured using an externally validated convolutional neural network model. Among the 146 included patients, nasogastric tube feeding was successfully transitioned to oral feeding in 46.6%. After adjusting for covariables related to successful weaning, skeletal muscle areas, indices, and volume indices were positively associated with successful nasogastric tube weaning. Although VFSS results and skeletal muscle parameters alone showed suboptimal performance for predicting successful weaning, a prediction model combining skeletal muscle index at the T4 level and VFSS results improved the prediction performance to an acceptable level (AUC ≥ 0.7). Skeletal muscle index measured at the T4 level may be a useful supplementary indicator for predicting successful weaning from nasogastric tube feeding in patients with aspiration pneumonia.

Stability of Direct Oral Anticoagulants Concentrations in Blood Samples for Accessibility Expansion of Chromogenic Assays

Background and Objectives: Direct oral anticoagulants (DOACs) are used for minimising the risk of thromboembolic events. In clinical practice, there is no need to measure DOAC concentration in the routine. Nevertheless, there are cases where such measurements are necessary, as the European Society of Cardiology's guideline recommends. However, determining DOAC levels is not available for everyone due to chromogenic assay availability limitations from sample storage problems, as tests are performed only in a few healthcare settings. This study aimed to assess whether more applicable storage conditions could be used for transportation to provide chromogenic assays for outpatient healthcare and other hospitals' practices. Materials and Methods: Chromogenic assays measuring anti-FXa (for rivaroxaban and edoxaban) and anti-FIIa (for dabigatran) were used. Concentrations were determined immediately after blood collection as baseline value: (1) after the storage of citrated whole blood in refrigerator (+2-8 °C); (2) of citrated plasma in refrigerator (+2-8 °C); and (3) of citrated frozen plasma (-20 °C) on the third and seventh days of storage. Acceptable change limits were considered stable if the deviation did not exceed ±20% of the baseline value. Results: The median (Cl 95%) baseline value of rivaroxaban was 168 (147-236) ng/mL; of dabigatran 139 (99-178) ng/mL; and of edoxaban-174 (135-259) ng/mL. The median deviation from a baseline value stored as citrate whole blood samples (+2-8 °C) was 5.4% and 3.4%; as citrated plasma (+2-8 °C) was 0.4% and -0.6%; and as citrated frozen plasma (-20 °C) was -0.2% and 0.2% on the third and seventh days of storage, respectively. Conclusions: Our data suggest that whole blood samples stored in a refrigerator, as well as citrated plasma samples stored in both the refrigerator and freezer, preserve DOAC concentration stable at +2-8 °C or -20 °C for up to 7 days, and are suitable for transportation, except for low-concentration samples.

Early Experience with the Paul Glaucoma Implant in Childhood Glaucoma: A Case Series

Purpose

The Paul glaucoma implant (PGI, Advanced Ophthalmic Innovations, Singapore, Republic of Singapore) is a recently developed novel non-valved glaucoma drainage device (GDD) designed to effectively reduce the intraocular pressure (IOP) in glaucoma patients with a theoretically reduced risk of postoperative complications such as hypotony, endothelial cell loss, strabismus, and diplopia. Limited literature has evaluated its use in adult glaucoma; however, its use in pediatric glaucoma has not been reported to date. We present our early experience with PGI in refractory childhood glaucoma.

Patients and Methods

This study was retrospective single-surgeon case series in a single tertiary center.

Results

Three eyes of 3 patients with childhood glaucoma were enrolled in the study. During nine months of follow-up, postoperative IOP and number of glaucoma medications were significantly lower than preoperative values in all the enrolled patients. None of the patients developed postoperative complications including postoperative hypotony, choroidal detachment, endophthalmitis, or corneal decompensation.

Conclusion

PGI is an efficient and relatively safe surgical treatment option in patients with refractory childhood glaucoma. Further studies with larger number of participants and longer follow-up period are required to confirm our encouraging results.

Direct Fabrication of a Copper RTD over a Ceramic-Coated Stainless-Steel Tube by Combination of Magnetron Sputtering and Sol-Gel Techniques

Reducing the economic and environmental impact of industrial process may be achieved by the smartisation of different components. In this work, tube smartisation is presented via direct fabrication of a copper (Cu)-based resistive temperature detector (RTD) on their outer surfaces. The testing was carried out between room temperature and 250 °C. For this purpose, copper depositions were studied using mid-frequency (MF) and high-power impulse magnetron sputtering (HiPIMS). Stainless steel tubes with an outside inert ceramic coating were used after giving them a shot blasting treatment. The Cu deposition was performed at around 425 °C to improve adhesion as well as the electrical properties of the sensor. To generate the pattern of the Cu RTD, a photolithography process was carried out. The RTD was then protected from external degradation by a silicon oxide film deposited over it by means of two different techniques: sol-gel dipping technique and reactive magnetron sputtering. For the electrical characterisation of the sensor, an ad hoc test bench was used, based on the internal heating and the external temperature measurement with a thermographic camera. The results confirm the linearity (R² > 0.999) and repeatability in the electrical properties of the copper RTD (confidence interval < 0.0005).

Cyclization of an Achiral Flipping Panel to Homochiral Tubes Exhibiting Circularly Polarized Luminescence

Macrocyclization of the bendable 2,7-dimethoxythianthrene with methylene linkages afforded a pair of homochiral macrocycles featuring a hex-nut-like geometry. Their structures were fully characterized by nuclear magnetic resonance spectroscopy, mass spectrometry, and single crystal X-ray diffraction analysis. Their stable planar chirality facilitates efficient resolution of the pair of enantiomers which could be readily derivatized. Installing phenylethynyl groups on their rims leads to luminescent tubular macrocycles exhibiting circularly polarized luminescence with a large dissymmetry value |glum| of 5 × 10-3. Supramolecular binding of electron-deficient guests by the tube results in fluorescence quenching proved its potentials for future development of switchable chiroptical systems.

A Narrative Review of Traumatic Pneumothorax Diagnoses and Management

BACKGROUND

Correct identification and rapid intervention of a traumatic pneumothorax is necessary to avoid hemodynamic collapse and subsequent morbidity and mortality. The purpose of this clinical review is to summarize the evaluation and best treatment strategies to improve outcomes in combat casualties. Blunt, explosive, and penetrating trauma are the 3 etiologies for causing a traumatic pneumothorax. Blunt trauma tends to be more common, but all etiologies require similar treatment. The current standard to diagnose pneumothorax is through imaging to include ultrasound, chest x-ray, or computed tomography. A physical exam aids in the diagnosis especially when few other resources are available. Recent studies on the treatment of a small, closed pneumothorax involve conservative care, which includes close observation of the patient and monitoring supplemental oxygen. For a large, closed pneumothorax, conservative treatment is still a possible option, but manual aspiration may be required. Less often, a needle or tube thoracostomy is needed to reinflate the lung. Large, open pneumothoraxes require the most invasive treatment with current guidelines recommending tube thoracostomy. More invasive management options can result in higher rates of complications. Given the significant variability in practice patterns, most notable in resource limited settings, the areas for potential research are presented.

A Narrative Review of Traumatic Pneumothorax Diagnoses and Management

BACKGROUND

Correct identification and rapid intervention of a traumatic pneumothorax is necessary to avoid hemodynamic collapse and subsequent morbidity and mortality. The purpose of this clinical review is to summarize the evaluation and best treatment strategies to improve outcomes in combat casualties. Blunt, explosive, and penetrating trauma are the 3 etiologies for causing a traumatic pneumothorax. Blunt trauma tends to be more common, but all etiologies require similar treatment. The current standard to diagnose pneumothorax is through imaging to include ultrasound, chest x-ray, or computed tomography. A physical exam aids in the diagnosis especially when few other resources are available. Recent studies on the treatment of a small, closed pneumothorax involve conservative care, which includes close observation of the patient and monitoring supplemental oxygen. For a large, closed pneumothorax, conservative treatment is still a possible option, but manual aspiration may be required. Less often, a needle or tube thoracostomy is needed to reinflate the lung. Large, open pneumothoraxes require the most invasive treatment with current guidelines recommending tube thoracostomy. More invasive management options can result in higher rates of complications. Given the significant variability in practice patterns, most notable in resource limited settings, the areas for potential research are presented.

Formation and composition of crust in the nephrostomy tube of patients undergoing percutaneous nephrostomy

To investigate the formation and composition of crust in the nephrostomy tube (NT) of patients undergoing percutaneous nephrostomy (PCN). Consecutive patients undergoing PCN for the treatment of obstructive nephropathy who then underwent NT exchange between January 2020 and May 2022 were included in the study. The composition of crust in NTs was analyzed using infrared spectrum automatic analysis system. A total of 46 NTs were collected from 46 consecutive patients (19 men, 27 women; mean age, 68.5 ± 13.4 years) who underwent PCN. The median indwelling time of NTs was 96 days (Q1, 90 days; Q3, 140 days). Among the 46 NTs, 20 (43.5%) were positive for the presence of crust. The mean indwelling time was significantly longer in NTs positive for crust than in those negative for crust (169.7 ± 55.7 days vs 86.5 ± 15.0 days; P < .01). In the NTs positive for crust, the crust was composed of mixed components (apatite carbonate and magnesium ammonium phosphate hexahydrate, n = 7; apatite carbonate and calcium oxalate monohydrate, n = 4) in 11 NTs and a single component (apatite carbonate, n = 5; anhydrous uric acid, n = 2; calcium oxalate monohydrate, n = 2) in 9 NTs. When the NT indwelling time was longer than 3 months, the incidence of crust formation in the NT was significantly increased. Crust was most commonly composed of mixed components. In light of these findings, we suggest that NTs should be exchanged every 3 to 4 months to prevent the formation of crust and thus prevent obstruction of the NT.

Quasi-Static Compression Properties of Bamboo and PVC Tube Reinforced Polymer Foam Structures

In recent years, there has been a growing interest for composite materials due to the superior capability to absorb energy and lightweight factor. These properties are compatible to be utilized in the development for transportation system as it can reduce the fuel consumption and also minimize the effect of crash to the passenger. Therefore, the aim for this project is to study the compression strength and energy absorbing capability for Polyvinyl chloride (PVC) and bamboo tubes reinforced with foam. Several parameters are being considered, these being the effect of single and multiple tube reinforced foam structure, foam density, diameter of the tube as well as effect of different crosshead speed. The results showed that increasing the relative foam density will led to an increase in the compression strength and specific energy absorption (SEA) values. Furthermore, a significant increase of compression strength can be seen when several tubes are introduced into the foam while SEA remained almost the same. Finally, the influence of crosshead below 20 mm/min did not vary significantly for both compression strength and SEA.

Transportation of a commercial premixed intravenous insulin product through a pneumatic tube system

PURPOSE

Delivery of insulin products via pneumatic tubes is often avoided in health systems, as agitation may cause insulin proteins to destabilize, resulting in loss of function through denaturation, aggregation, or other processes. The actual loss of potency due to delivery via pneumatic tubes has not been reported for new, ready-to-use insulin products.

METHODS

Samples were drawn from 7 commercial intravenous (IV) bags containing a 100 units/100 mL premixed solution of regular insulin in sodium chloride injection (Myxredlin, Baxter). The bags were then exposed to 7 unique long-distance pneumatic tube routes. The post-transportation bags were visually inspected for evidence of foaming. Samples were drawn from the post-transportation bags and insulin concentrations were analyzed via an enzyme immunoassay and compared to pretransportation concentrations.

RESULTS

All seven post-transportation insulin samples were within 10% of their respective pretransportation sample. No foaming was observed in any of the Myxredlin bags after transportation through the pneumatic tube system.

CONCLUSION

Transporting 100 unit/100 mL Myxredlin i.v. bags through a pneumatic tube system does not result in a clinically significant loss of potency. Therefore, delivery of this drug product via a pneumatic tube system to patient care areas can be considered in daily practice.

The Drosophila miR-959-962 Cluster Members Repress Toll Signaling to Regulate Antibacterial Defense during Bacterial Infection

MicroRNAs (miRNAs) are a class of ~22 nt non-coding RNA molecules in metazoans capable of down-regulating target gene expression by binding to the complementary sites in the mRNA transcripts. Many individual miRNAs are implicated in a broad range of biological pathways, but functional characterization of miRNA clusters in concert is limited. Here, we report that miR-959-962 cluster (miR-959/960/961/962) can weaken Drosophila immune response to bacterial infection evidenced by the reduced expression of antimicrobial peptide Drosomycin (Drs) and short survival within 24 h upon infection. Each of the four miRNA members is confirmed to contribute to the reduced Drs expression and survival rate of Drosophila. Mechanically, RT-qPCR and Dual-luciferase reporter assay verify that tube and dorsal (dl) mRNAs, key components of Toll pathway, can simultaneously be targeted by miR-959 and miR-960, miR-961, and miR-962, respectively. Furthermore, miR-962 can even directly target to the 3' untranslated region (UTR) of Toll. In addition, the dynamic expression pattern analysis in wild-type flies reveals that four miRNA members play important functions in Drosophila immune homeostasis restoration at the late stage of Micrococcus luteus (M. luteus) infection. Taken together, our results identify four miRNA members from miR-959-962 cluster as novel suppressors of Toll signaling and enrich the repertoire of immune-modulating miRNA in Drosophila.

A Feasibility Study for 3D-printed Poly(methyl methacrylate)-resin Tracheostomy Tube Using a Hamster Cheek Pouch Model

BACKGROUND/AIM

A three-dimensional (3D) printed tracheostomy tube has potential application for patients who require a specialized tube. The aim of this study was to evaluate the characteristics of various 3D printing materials and determine their use in producing 3D-printed tracheostomy tube.

MATERIALS AND METHODS

Mechanical, chemical, and microbiological in vivo changes in the scaffolds were analyzed using a hamster cheek pouch (HCP) model.

RESULTS

The poly methyl methacylate (PMMA)-resin showed superior pre- and post-insertion mechanical properties and a relatively consistent lower biofilm formation compared with other scaffolds. PMMA-resin was successfully 3D-printed with dimensional accuracy without a support system. The use of a 3D-printed PMMA tracheostomy tube in a rabbit trachea showed no definite signs of infection, allergy or foreign body reaction.

CONCLUSION

PMMA-resin can be proposed as an alternative for a 3D-printed tracheostomy tube material. In addition, we suggest HCPs as an in vivo model for evaluating indwelling medical devices.

Descemet membrane endothelial keratoplasty in patients with prior glaucoma surgery

OBJECTIVE

To present outcomes of Descemet membrane endothelial keratoplasty (DMEK) in eyes with prior trabeculectomy or a glaucoma drainage device (GDD).

METHODS

A retrospective case series, including patients that had previously undergone trabeculectomy and/or GDD implantation, who later underwent DMEK between 2013 and 2016 at Toronto Western Hospital and the Kensington Eye Institute. Outcome measures: best spectacle-corrected visual acuity (BSCVA), endothelial cell (EC) density, intraoperative and postoperative complications.

RESULTS

Twenty-seven eyes of 27 patients were included. All DMEK procedures were uneventful. Mean follow-up time was 14.6 ± 6.1 months. In eyes with no visually limiting comorbidities (n = 16), BSCVA improved from 1.34 ± 0.65 logMAR (Snellen equivalent ~20/440) preoperatively to 0.51 ± 0.24 logMAR (Snellen equivalent ~20/65) and 0.50 ± 0.33 logMAR (Snellen equivalent ~20/65) at 6 and 12 months, respectively (p < 0.001 for both). In eyes with visually limiting comorbidities (n = 11), BSCVA improved from 1.92 ± 0.72 logMAR (Snellen equivalent ~20/1665) preoperatively to 1.43 ± 0.83 logMAR (Snellen equivalent ~20/540) and 1.37 ± 0.99 logMAR (Snellen equivalent ~20/470) at 6 and 12 months, respectively (p = 0.008 and p = 0.037).Graft detachment rate was 24.1% and rebubble rate was 17.2%. Primary and secondary graft failure rates were 3.7% and 10.3%, respectively. Rejection rate was 17.2%. EC-loss rate at 6 months and 12 months was 36.7% and 50.5%, respectively.

CONCLUSIONS

DMEK performed in eyes with previous trabeculectomy or a GDD is more challenging than conventional DMEK, but has good outcomes. Higher rates of graft rejection and secondary graft failure in this setting should be further evaluated in long-term studies.

Comparison of Conventional Tube and Gel-Based Agglutination Tests for AB System Blood Typing in Cat

Gel technology is widely used for blood typing in human medicine. It has a number of advantages over routine tube testing, including standardization, stability, smaller sample volume, ease of performance and analysis, and speed. The aim of this study was to evaluate feline blood typing using the gel column technique. TUBE agglutination typing was performed in 143 feline blood samples from blood donors and recipients, healthy and sick patients, and whole-blood units anticoagulated with ethylenediamine tetraacetic acid or citrate phosphate dextrose adenine. Plasma from type B cats was used as anti-A reagent, Triticum vulgaris lectin as anti-B reagent, and the control was saline solution. Agglutination in backtyping of types B and AB samples with type A red blood cells (RBCs) was used to confirm whether the samples were type B (presence of alloantibodies) or type AB (absence of alloantibodies). Blood typing in a neutral gel column technique (GEL) using the same anti-A and anti-B reagents was performed on duplicate samples. Sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, positive predictive value, negative predictive value, overall accuracy, and Cohen κ coefficient (κ) for GEL were calculated, with TUBE considered the gold standard technique. Of 143 samples typed with TUBE, 98 (68.5%) were type A, 25 (17.5%,) type B, and 20 (14.0%) type AB. Backtyping confirmed the categorization of all types B and AB samples. Of these samples, gel testing produced 115 (80.4%) concordant results; a mixed-field agglutination pattern (layers of RBCs at both the top and at the bottom of the gel in either the A or B gel column) was seen in 27 samples, and one type B sample was misidentified as type AB. If the mixed-field pattern was interpreted as a negative result, 141/143 (98.6%) samples showed concordant results with an overall accuracy of the GEL of 100.0% for type A, 98.9% for type B, and 99.1% for type AB. Strength of agreement was very good (κ = 0.97). When the same anti-A and anti-B reagents are used, GEL is a sensitive and specific method for blood typing feline samples. Until additional studies have been performed, mixed-field patterns obtained in GEL testing should be classified as negative results.

Colonization rates of tracheostomy tubes associated with the frequency of tube changes

BACKGROUND

Tracheostomy-tube change protocols are implemented primarily due to concern regarding infections. Currently changes vary from within 4 weeks post-insertion to 3 monthly thereafter. However, currently no evidence-based guidelines exist to justify these protocols. This study aims to assess the colonization of tracheostomy-tubes associated with the frequency of changes.

METHODS

A prospective cohort study over 18-months of adult tracheostomy patients at a single institution (inpatient/outpatients). Patients were grouped based on whether tubes were changed at ≤4 weeks or >4 weeks and microbiology swabs sent for microscopy, culture and sensitivities.

RESULTS

A total of 65 patients were enrolled. No statistically significant difference in colonization in patients undergoing tube changes more than every 4 weeks to those less than every 4 weeks was found (56.2% versus 57.1%, χ² = 0.004, P = 0.95).

CONCLUSION

The timing of tracheostomy-tube changes may not affect colonization and infection rates. Routine changes for the purpose of reducing infection risk may not be needed unless clinically indicated.

Transverse Circular Holes in Cylindrical Tubes Loaded in Traction and in Flexion: A New Analytical Approximation of the Stress Concentration Factor

This paper presents an analytic formula for the theoretical stress concentration factor kt for cylindrical tubes with transverse circular holes, loaded in traction or in flexion. The study is based on modern finite element (FEM) techniques, which allow for appreciating with great accuracy the phenomenon of stress concentration. A comparison between the FEM results of this paper and those that were obtained by the existing analytic formulas shows the need of an update, as some discrepancies may be noticed. Our results are the fruit of a wide campaign of numerical FEM simulations that have been conducted analyzing numerous geometric configurations of the tube. Moreover, these configurations are defined in a wider two-dimensional (2-D) domain than the one valid for previous analytic formulas published in literature. Finally, these FEM results have been approximated with great accuracy by means of a fourth degree double polynomial regression that led to the new analytic formula that is proposed in this paper.

Proof of Concept for a Polyethylene Glycol/Gel Hybrid Testing Method

OBJECTIVE

To test a hybrid polyethylene glycol (PEG)/gel method, specifically to attempt to increase reaction strength of accidentally overdiluted anti-Cob and broadly for proof of concept.

METHODS

Methods were divided into 2 basic steps: sensitization and antiglobulin (AHG) testing. Sensitization was performed with PEG tubes, followed by AHG using the gel method. One wash was performed between the 2 steps. We tested 7 plasma antibody specimens.

RESULTS

In addition to the first specimen, 6 additional antibodies were selected for detection by the PEG/gel hybrid method. Antibody reactivity was detected in all specimens tested with both methods. The PEG/gel method yielded enhanced reactivity in 3 of 7 antibodies (42.9%) and the equivalent of enhanced reactivity in 4 of 7 antibodies tested (57.1%).

CONCLUSION

The reactivity of diluted anti-Cob (specimen 1) was increased; thus, our concept proved to be viable. The hybrid PEG/gel method showed the equivalent of enhanced or enhanced reactivity with all specimens tested and provided a stable medium.

An Automated Method for Direct Antiglobulin Testing and the Resulting Amount of Phototherapy Used at a Large Academic Medical Center

OBJECTIVE

To evaluate how clinical practice was affected by the change in direct antiglobulin testing (DAT) methodologies and subsequent stronger reported DAT results at our large academic medical center.

METHOD

We retrospectively reviewed DAT results of umbilical cord blood from infants with blood type A or B born to mothers with antibody-negative type O blood, based on records kept at the University of Alabama at Birmingham (UAB) Hospital, a 1400-bed academic medical center.

RESULTS

We randomly chose 50 neonates with positive DAT results who had been tested using the tube method and 50 whose testing had used the gel method. Although 86% of results with the tube method were positive microscopically, 52% and 40% of the DAT results with the gel method were 1+ and 2+ positive, respectively. Further, we observed an increase in the number of neonates treated with phototherapy who had been tested using the gel method.

CONCLUSION

We report that DATs performed using the gel method had increased DAT strength compared with tube testing, which led to increased use of phototherapy by our clinical colleagues.

MEMS-Based Sensor for Simultaneous Measurement of Pulse Wave and Respiration Rate

The continuous measurements of vital signs (body temperature, blood pressure, pulse wave, and respiration rate) are important in many applications across various fields, including healthcare and sports. To realize such measurements, wearable devices that cause minimal discomfort to the wearers are highly desired. Accordingly, a device that can measure multiple vital signs simultaneously using a single sensing element is important in order to reduce the number of devices attached to the wearer's body, thereby reducing user discomfort. Thus, in this study, we propose a device with a microelectromechanical systems (MEMS)-based pressure sensor that can simultaneously measure the blood pulse wave and respiration rate using only one sensing element. In particular, in the proposed device, a thin silicone tube, whose inner pressure can be measured via a piezoresistive cantilever, is attached to the nose pad of a pair of eyeglasses. On wearing the eyeglasses, the tube of sensor device is in contact with the area above the angular artery and nasal cavity of the subject, and thus, both pulse wave and breath of the subject cause the tube's inner pressure to change. We experimentally show that it is possible to extract information related to pulse wave and respiration as the low-frequency and high-frequency components of the sensor signal, respectively.

A comparison of stability of chemical analytes in plasma from the BD Vacutainer® Barricor™ tube with mechanical separator versus tubes containing gel separator

BACKGROUND

There is a need of prolonged stability of certain chemical analytes in lithium heparin tubes with separators. A new tube with a mechanical separator has recently been launched (Barricor™), which according to the manufacturer may have these benefits. The aim of this study was to evaluate stability performance of this tube in comparison with plasma gel tubes under clinically realistic circumstances.

METHODS

Blood was collected in tubes containing lithium heparin with different separators; gel separator (Vacutainer^® PST™, Becton Dickinson and Vacuette^® , Greiner bio-one) and mechanical separator (Vacutainer^® Barricor™, Becton Dickinson). All tubes had an aspiration volume of 3 mL and were centrifuged at similar time and force. Tubes were transported manually or by car. Seven analytes from 122 patients were analyzed after 3 to 80 hours by Cobas c701 (Roche).

RESULTS

The Barricor™ tube showed increased stability of phosphate and potassium and similar stability of aspartate aminotransferase, glucose, homocysteine, lactate dehydrogenase, and magnesium compared with gel tubes. Maximal allowable bias for phosphate was exceeded after 68 hours for Barricor™ tubes compared with 29 or 35 hours for gel tubes and for potassium after 40 hours for Barricor™ tubes vs 9 or 12 hours for gel tubes. Transportation did not affect stability. Hemolysis index was slightly lower in Barricor tubes than in gel tubes (P = .01).

CONCLUSION

Implementing the new Barricor™ tube will improve stability of potassium and phosphate in plasma. Blood sampling facilities far from the laboratory may benefit from using these tubes, thus diminishing preanalytical errors.

The Use of Environmental Enrichments Affects Performance and Behavior of Growing Rabbits Housed in Collective Pens

Simple Summary

Group housing of growing rabbits is currently used in commercial farms to improve animal welfare. However, these systems have shown some weaknesses, mainly associated with the aggressive behavior exhibited among rabbits. Environmental enrichment can offer additional space and a sheltered area in which an animal can protect itself from pen mates, but studies in rabbits under farming conditions are scarce. Thus, this study evaluated the use of two types of enrichment (an elevated plastic-slatted platform and/or a plastic hiding tube) in rabbits housed in collective pens within large groups during the growing period. The use of the platform allowed rabbits to move up/down, to rest in a more comfortable position and to increase explorative behavior, without modifying production performance. However, more injured rabbits were found at the end of the trial in pens with platforms. The presence of the tube impaired growth performance and did not modify behavior. Hence, elevated platforms have been shown to work as a structural enrichment in group-housed rabbits, whereas the usefulness of the tube remains questionable.

Abstract

This study assessed the effects of an elevated plastic-slatted platform and/or a plastic hiding tube in collective pens with large group sizes (27 or 36 rabbits/pen; 16 rabbits/m²) on the performance and welfare of rabbits kept from weaning (at 33 days of age) to slaughter (at 68 or 75 days of age). Growth performance, injuries, and behavior (video recorded for 24 h) of rabbits (n = 504) were recorded. The platform allowed rabbits to adopt the rearing position more frequently (+0.14 events during 2 min every 30 min across 24 h) and to rest with stretched body for longer (+3.8% of observed time) (p ≤ 0.001). Production parameters and reactivity at the open field test were not modified, but the occurrence of injured rabbits at the trial end was higher in pens with platforms (+8.9%; p ≤ 0.01). This result was possibly related to the higher group size in pens with platforms (36 rabbits) compared to those without platforms (27 rabbits). The inclusion of the tube decreased growth (−2.2 g/d; p ≤ 0.05), whereas it was scarcely used by rabbits and it did not substantially change their behavior or the occurrence of injuries. In conclusion, under the experimental conditions of this study, elevated platforms worked as a useful structural enrichment in view of animal behavior but negatively impacted on the rate of injuries, whereas the usefulness of the tube was not confirmed.

Graphene-Based Wireless Tube-Shaped Pressure Sensor for In Vivo Blood Pressure Monitoring

We propose a wireless pressure sensor composed of a graphene sheet and a transmitter coil integrated with a polydimethylsiloxane (PDMS) tube. The pressure inside the tube was monitored wirelessly using an external receiver coil. We then monitored the typical blood pressure range, 12–20 kPa, using this fabricated sensor by changing the turn number of the receiver coil and the overlapping length of the coils. Furthermore, we demonstrated wireless blood pressure measurement by connecting our sensor to the blood vessel of a rat. Our results suggested that this sensor can be easily inserted between an implantable medical device and blood vessels for in vivo blood pressure monitoring. The proposed wireless pressure sensor could also be suitable for monitoring in vivo implanted medical systems, such as artificial organs and pump systems.

Comparison of cross-matching method for detection of DEA 7 blood incompatibility

We compared 3 major cross-match (XM) tests to identify dog erythrocyte antigen (DEA) 7 blood incompatibilities in dogs as a result of anti-DEA 7 antibodies: gel (GEL), standard tube (TUBE) agglutination, and immunochromatography strips (STRIP). Blood samples from 42 dogs were typed for DEA 7; 2 tested DEA 7-positive (DEA 7+). The 40 DEA 7-negative (DEA 7-) plasma samples were cross-matched against the 2 DEA 7+ and 3 DEA 7- red blood cell (RBC) samples by GEL to identify samples with anti-DEA 7 antibodies. Twenty DEA 7- plasma samples without and with anti-DEA 7 antibodies were cross-matched with samples of the 2 DEA 7+ RBCs in a double-blind fashion using the TUBE and STRIP XM methods. GEL results were used as the reference method for comparison. To determine relationships between results, 2 × 2 tables were used. Cohen kappa coefficient (κ) was calculated between results of GEL and the other 2 methods. With GEL, 21 of 40 XM tests were positive and 19 of 40 negative for anti-DEA 7 antibodies. The same results were obtained by TUBE, whereas only 1 of 40 XM tests was positive by STRIP. There was a statistically significant relationship between results of GEL and TUBE ( p < 0.000) with perfect agreement (κ = 1.000), but not between GEL and STRIP results ( p = 1.000) in which agreement was equivalent to chance (κ = 0.0453). The GEL and TUBE XM tests, but not STRIP, are useful methods for identification of DEA 7 incompatibilities caused by anti-DEA 7 antibodies.

Crystal Structures of R-Type Bacteriocin Sheath and Tube Proteins CD1363 and CD1364 From Clostridium difficile in the Pre-assembled State

Diffocins are high-molecular-weight phage tail-like bacteriocins (PTLBs) that some Clostridium difficile strains produce in response to SOS induction. Similar to the related R-type pyocins from Pseudomonas aeruginosa, R-type diffocins act as molecular puncture devices that specifically penetrate the cell envelope of other C. difficile strains to dissipate the membrane potential and kill the attacked bacterium. Thus, R-type diffocins constitute potential therapeutic agents to counter C. difficile-associated infections. PTLBs consist of rigid and contractile protein complexes. They are composed of a baseplate, receptor-binding tail fibers and an inner needle-like tube surrounded by a contractile sheath. In the mature particle, the sheath and tube structure form a complex network comprising up to 200 copies of a sheath and a tube protein each. Here, we report the crystal structures together with small angle X-ray scattering data of the sheath and tube proteins CD1363 (39 kDa) and CD1364 (16 kDa) from C. difficile strain CD630 in a monomeric pre-assembly form at 1.9 and 1.5 Å resolution, respectively. The tube protein CD1364 displays a compact fold and shares highest structural similarity with a tube protein from Bacillus subtilis but is remarkably different from that of the R-type pyocin from P. aeruginosa. The structure of the R-type diffocin sheath protein, on the other hand, is highly conserved. It contains two domains, whereas related members such as bacteriophage tail sheath proteins comprise up to four, indicating that R-type PTLBs may represent the minimal protein required for formation of a complete sheath structure. Comparison of CD1363 and CD1364 with structures of PTLBs and related assemblies suggests that several conformational changes are required to form complete assemblies. In the sheath, rearrangement of the flexible N- and C-terminus enables extensive interactions between the other subunits, whereas for the tube, such contacts are primarily established by mobile α-helices. Together, our results combined with information from structures of homologous assemblies allow constructing a preliminary model of the sheath and tube assembly from R-type diffocin.

A Tube-Integrated Painted Biosensor for Glucose and Lactate

Developing a simple and direct approach for sensitive, specific, and rapid detection of metabolic compounds is of great importance for a variety of biological, medical, and food applications. Tubes are a highly portable and accessible container shape which are widely used for scientific research in cell biology and chemical synthesis, and which are also of great use in domestic health care applications. Here, we show for the first time the development of a tube-based painted amperometric biosensor for the detection of glucose and lactate. The sensor was prepared by printing carbon graphite and silver/silver chloride inks on the interior wall of the tube and then immobilizing glucose oxidase or lactate oxidase on the sensor. The sensor showed a sensitive, rapid, and reliable detection of glucose and lactate. We anticipate that these results could open new avenues for the development of painted biosensors, and toward advanced biosensor applications.

Poly-L-lactic Acid (PLLA)-Chitosan-Collagen Electrospun Tube for Vascular Graft Application

Poly-L-Lactic acid (PLLA) blended with chitosan and collagen was used to fabricate a conduit for blood vessel engineering through an electrospinning process. Various concentrations of chitosan were used in the blend in order to study its effect on the morphology, chemical bond, tensile strength, burst pressure, hemocompatibility, and cell viability (cytotoxicity) of the tube.In vitro assessments indicated that addition of chitosan-collagen could improve cell viability and hemocompatibility. Best results were demonstrated by the conduit with 10% PLLA, 0.5% chitosan, and 1% collagen. Tensile strength reached 2.13 MPa and burst pressure reached 2593 mmHg, both values that are within the range value of native blood vessel. A hemolysis percentage of 1.04% and a cell viability of 86.2% were obtained, meeting the standards of high hemocompatibility and low cytotoxicity for vascular graft material. The results are promising for further development toward vascular graft application.

Finite Element Analysis of Tunable Composite Tubes Reinforced with Auxetic Structures

A tubular composite structure that is built of two materials, characterized by different Young moduli, is analysed in this paper. The Young's modulus of one of these materials can be controlled by external conditions e.g., magnetic or electric field, temperature etc. The geometry of the reinforcement is based on typical auxetic re-entrant honeycomb cellular structure. The influence of this external factor on the behaviour of the stretched tube is analysed in this paper. Also, the possibility of creating a tubular composite structure whose cross-section is either shrinking or expanding, while stretching the tube is presented.

Grafts in Glaucoma Surgery: A Review of the Literature

Patients with bleb leakage, dehiscence, or infection after trabeculectomy need urgent bleb salvaging to prevent vision loss. Patients who have undergone a glaucoma drainage device surgery may have tube erosion, which is yet another devastating and outcome-compromising complication. The bleb or the tube in such cases needs to be patched by a biologic tissue, which is roofed by the conjunctiva and acts as a barrier against external infections. Sclera, pericardium, cornea, and dura mater are the commonly used patch graft materials. This review reports the outcomes of several new and old graft materials used to repair the post trabeculectomy compromised bleb and tube exposure in glaucoma drainage device surgeries.

Comparison between traditional and small-diameter tube-assisted bronchoscopic balloon dilatation in the treatment of benign tracheal stenosis

OBJECTIVE

To compare the safety and efficacy between using a small-diameter tube-assisted bronchoscopic balloon dilatation (BBD) and the traditional BBD in the treatment of benign tracheal stenosis.

METHODS

A retrospective study included 58 patients with benign tracheal stenosis from August 2009 to December 2014 was made. The patients who underwent traditional BBD were divided into group A, and who underwent a small-diameter tube-assisted BBD were divided into group B. The tracheal diameter, dyspnea index and blood gas analysis results were detected before and after BBD. Efficacy and complications were evaluated after BBD.

RESULTS

There were significant differences in oxygen saturation (PaO₂ ) during the operations comparing with before and after operations in group A (P = .005), while there was no significant difference in group B (P = .079). The tracheal diameter obviously increased (in group A, from 4.16 ± 1.43 mm to 12.47 ± 1.41 mm, P = .000; in group B: from 4.94 ± 1.59 mm to 12.61 ± 1.41 mm, P = .000). Dyspnea index obviously decreased (group A: from 3.21 ± 0.93 to 0.50 ± 0.59, P = .000; group B: from 3.24 ± 0.89 to 0.65 ± 0.69, P = .000). The immediately cure rate in both groups was 100%. Long-term effect was significantly better in group B than that in group A (85.3% vs 59.1%, P = .021), at the end of the follow-up period.

CONCLUSIONS

Small-diameter tube-assisted BBD obtains better safety and long-term efficacy than the traditional BBD in the treatment of benign tracheal stenosis. However, close attention should be given to the risk of the adverse effects caused by carbon dioxide retention.

A Novel Extrusion for Manufacturing TiBw/Ti6Al4V Composite Tubes with a Quasi-Continuous Reinforced Structure

The present work introduces a novel extrusion with filler material to produce the high-performance TiBw/Ti-6Al-4V composite tube with a quasi-continuous reinforced structure. A simulation was adopted to study the effect of the filler material on the shape accuracy of the tubes. Based on the simulation results, the flow stress of the filler material was not the important factor, but the friction coefficient between the filler and TiBw/Ti-6Al-4V composite and the canning shape were critical to the tube precision. The microstructure and mechanical performance for the as-extruded TiBw/Ti-6Al-4V composite tubes were systematically investigated. After extrusion, the transverse section microstructure of the TiBw/Ti6Al4V composite tube remained quasi-continuous and the TiBw were rotated to align the extrusion direction. Moreover, the tensile strength and elongation reached 1240 MPa and 13.5%, resulting from dynamic recrystallization and whisker rotation.

[Serial Cases of Troubleshooting of NeuViz CT]

The article describes the specific examples of fault maintenance of the Neusoft NeuViz series CT, so as to provide some maintenance references for colleagues.

[Successive ectopic pregnancies associated with tubal shistosomiasis in a French traveler]

La bilharziose est la seconde endémie parasitaire mondiale et ses atteintes génito urinaires sont bien décrites. Les grossesses ectopiques (GEU) sur obstruction tubaire par les œufs de bilharziose sont rapportées dans les populations africaines. La bilharziose affecte aussi les voyageurs mais l'atteinte de l'appareil génital féminin est plus rare. Nous rapportons un cas exceptionnel de deux GEU successives sur bilharziose tubaire chez une patiente d'origine Française, sept ans après un voyage touristique au Mali, la première découverte sur pièce de salpingectomie et la seconde ayant nécessité une salpingotomie controlatérale avec une injection de méthotrexate, deux mois plus tard.

Assessment of three placement techniques for individualized positioning of the tip of the tracheal tube in children under the age of 4 years

BACKGROUND

Accurate positioning of the tip of the tracheal tube (tube tip) is challenging in young children. Prevalent clinical methods include placement of intubation depth marks, palpation of the tube cuff in the suprasternal notch, or deliberate mainstem intubation with subsequent withdrawal. To compare the predictability of tube tip positions, variability of the resulting positions in relation to the carina was determined applying the three techniques in each patient.

METHODS

In 68 healthy children aged ≤4 years, intubation was performed with an age-adapted, high-volume low-pressure cuffed tube adjusting the imprinted depth mark to the level of the vocal cords. The tube tip-to-carina distance was measured endoscopically. Thereafter, placements using (I) cuff palpation in the suprasternal notch and (II) auscultation to determine change in breath sounds during withdrawal after bronchial mainstem intubation were completed in random order.

RESULTS

Tube tip position above the carina was higher when using depth marks (mean = 36.8 mm) compared with cuff palpation in the suprasternal notch (mean = 19.0 mm). Variability, expressed as sd, was lowest with the mainstem intubation technique (5.2 mm) followed by the cuff palpation (7.4 mm) and the depth mark technique (11.2 mm) (P < 0.005).

CONCLUSION

Auscultation after deliberate mainstem intubation and cuff palpation resulted in a tube tip position above the carina that was shorter and more predictable than placement of the tube using depth markings.

Weaning children off enteral nutrition by netcoaching versus onsite treatment: a comparative study

AIM

The Graz model of tube weaning has been internationally recognised as a successful and rapid tube weaning program. Beside the onsite treatment option, a telemedical counselling was specifically developed in 2009. This study aims to show outcomes of this newly invented treatment in a large sample of patients.

METHODS

Our retrospective open-label study compared success of onsite versus telemedical Graz-based weaning methods for patients with diverse clinical diagnoses with either nasogastric, gastric or jejunal tubes. Outcome variables were successful transition to oral feeds, partial transition to night tube feeds, and failure or interruption of intervention. Patients and physicians chose the intervention method.

RESULTS

Complete weaning was achieved in 153 of 169 (90.5%) children in the netcoaching group versus 170 of 209 (81.3%) of those opting for onsite treatment (no significant differences, P > 0.05). Higher partial weaning rates were observed in the onsite group (15.3% vs. 4.7%, P < 0.01, degrees of freedom = 3, χ(2) = 22.76). There were no significant differences regarding the outcomes 'weaning trial without success' (netcoaching: 0% vs. onsite: 2.9%, P > 0.05) and 'interruption of programme' (netcoaching: 4.7% vs. onsite: 0.5%, P > 0.05) between the two groups.

CONCLUSION

Despite limitations of study design, we have demonstrated similar efficacy of Graz-based less expensive netcoaching versus more expensive onsite intervention in a large referral population with chronic tube dependency with the majority transitioning to complete oral feeds.

Facial nerve regeneration using basic fibroblast growth factor-impregnated gelatin microspheres in a rat model

Basic fibroblast growth factor (bFGF) plays a crucial role in the regeneration of peripheral nerve defects by affecting nerve cells, Schwann cells and fibroblasts, and by promoting axon outgrowth from the proximal nerve stump. However, the use of exogenous bFGF for in vivo regeneration of the peripheral nerves is limited by its short in vivo half-life. In this study, a drug delivery system for bFGF was developed that uses acidic gelatin hydrogel, which sustainably released bFGF in vivo over several weeks; its ability to promote peripheral nerve regeneration was also examined. In 8-week-old Lewis rats, 7-mm gaps were made in the buccal branch of the left facial nerve. Acidic gelatin hydrogel microspheres (10 µl) with or without bFGF (50 µg) were infused into a 10 mm silicone tube using a micropipette, and the silicone tube was then implanted into the gap. A 1-mm long nerve stump was inserted into each end of the tube. Histological examination at 7 weeks after implantation revealed (1) a significantly increased rate of nerve regeneration, (2) inducement of a number of regenerating nerve axons, and (3) a better degree of maturation of nerve axons in the bFGF microsphere group than that in the bFGF-free microsphere group. Copyright © 2014 John Wiley & Sons, Ltd.

Biocomposites reinforced by fibers or tubes as scaffolds for tissue engineering or regenerative medicine

As a dynamic and hierarchically organized composite, native extracellular matrix (ECM) not only supplies mechanical support, which the embedded cells need, but also regulates various cellular activities through interaction with them. On the basis of the ECM-mimetic principle, good biocompatibility and appropriate mechanical properties are the two basic requirements that the ideal scaffolds for the tissue engineering or regenerative medicine need. Some fibers and tubes have been shown effective to reinforce scaffolds for tissue engineering or regenerative medicine. In this review, three parts, namely properties affected by the addition of fibers or tubes, scaffolds reinforced by fibers or tubes for soft tissue repair, and scaffolds reinforced by fibers or tubes for hard tissue repair are stated, which shows that tissue repair or regeneration efficacy was enhanced significantly by fiber or tube reinforcement. In addition, it indicates that these reinforcing agents can improve the biocompatibility and biodegradation of the scaffolds in most cases. However, there are still some concerns, such as the homogeneousness in structure or composition throughout the reinforced scaffolds, the adhesive strength between the matrix and the fibers or tubes, cytotoxicity of nanoscaled reinforcing agents, etc., which were also discussed in the conclusion and perspectives part.

Air-coupled ultrasound stimulated optical vibrometry for resonance analysis of rubber tubes

Air-coupled ultrasound stimulated optical vibrometry is proposed to generate and detect the resonances of a rubber tube in air. Amplitude-modulated (AM) focused ultrasound radiation force from a broadband air-coupled ultrasound transducer with center frequency of 500 kHz is used to generate a low frequency vibration in the tube. The resonances of several modes of the tube are measured with a laser vibrometer of 633 nm wavelength. A wave propagation approach is used to calculate the resonances of the tube from its known material properties. Theoretical and experimental resonance frequencies agree within 5%. This method may be useful in measuring the in vitro elastic properties of arteries from the resonance measurements in air. It may also be helpful to better understand the coupling effects of the surrounding tissue and interior blood on the vessel wall by measuring the resonance of the vessel in vitro and in vivo.

Three-dimensional water diffusion in impermeable cylindrical tubes: theory versus experiments

Characterizing diffusion of gases and liquids within pores is important in understanding numerous transport processes and affects a wide range of practical applications. Previous measurements of the pulsed gradient stimulated echo (PGSTE) signal attenuation, E(q), of water within nerves and impermeable cylindrical microcapillary tubes showed it to be exquisitely sensitive to the orientation of the applied wave vector, q, with respect to the tube axis in the high-q regime. Here, we provide a simple three-dimensional model to explain this angular dependence by decomposing the average propagator, which describes the net displacement of water molecules, into components parallel and perpendicular to the tube wall, in which axial diffusion is free and radial diffusion is restricted. The model faithfully predicts the experimental data, not only the observed diffraction peaks in E(q) when the diffusion gradients are approximately normal to the tube wall, but their sudden disappearance when the gradient orientation possesses a small axial component. The model also successfully predicts the dependence of E(q) on gradient pulse duration and on gradient strength as well as tube inner diameter. To account for the deviation from the narrow pulse approximation in the PGSTE sequence, we use Callaghan's matrix operator framework, which this study validates experimentally for the first time. We also show how to combine average propagators derived for classical one-dimensional and two-dimensional models of restricted diffusion (e.g. between plates, within cylinders) to construct composite three-dimensional models of diffusion in complex media containing pores (e.g. rectangular prisms and/or capped cylinders) having a distribution of orientations, sizes, and aspect ratios. This three-dimensional modeling framework should aid in describing diffusion in numerous biological systems and in a myriad of materials sciences applications.