Boron nitride nanotube peapods at ultrasonic velocity impacts: A fully atomistic molecular dynamics investigation

Boron nitride nanotube peapods (BNNT-peapod) are composed of linear chains of C60
molecules encapsulated inside boron nitride nanotubes, they were first synthesized in 2003.
In this work, we investigated the mechanical response and fracture dynamics of BNNT-
peapods under ultrasonic velocity impacts (from 1 km/s up to 6 km/s) against a solid target.
We carried out fully atomistic reactive molecular dynamics simulations using a ReaxFF
forcefield. We have considered the case of horizontal and vertical shootings. Depending on
the velocity values, we observed nanotube bending, nanotube fracture, and C60 ejection.
Furthermore, the nanotube unzips for horizontal impacts at certain speeds, forming bi-layer
nanoribbons "incrusted" with C60 molecules. The methodology used here is applicable to
other nanostructures. We hope it motivates other theoretical investigations on the behavior
of nanostructures at ultrasonic velocity impacts and aid in interpreting future experimental
results. It should be stressed that similar experiments and simulations were carried out
on carbon nanotubes trying to obtain nanodiamonds. The present study expands these
investigations to include BNNT.

Tetra-penta-deca-hexagonal-graphene (TPDH-graphene) hydrogenation patterns: dynamics and electronic structure

The advent of graphene has renewed the interest in other 2D carbon-based materials. In particular, new structures have been proposed by combining hexagonal and other carbon rings in different ways. Recently, Bhattacharya and Jana have proposed a new carbon allotrope, composed of different polygonal carbon rings containing 4, 5, 6, and 10 atoms, named tetra-penta-deca-hexagonal-graphene (TPDH-graphene). This unusual topology results in interesting mechanical, electronic, and optical properties with several potential applications, including UV protection. Like other 2D carbon structures, chemical functionalizations can be used to tune TPDH-graphene's physical/chemical properties. In this work, we investigate the hydrogenation dynamics of TPDH-graphene and its effects on its electronic structure, combining DFT and fully atomistic reactive molecular dynamics simulations. Our results show that H atoms are mainly incorporated on tetragonal ring sites (up to 80% at 300 K), leading to the appearance of well-delimited pentagonal carbon stripes. The electronic structure of the hydrogenated structures shows the formation of narrow bandgaps with the presence of Dirac cone-like structures, indicative of anisotropic transport properties.

A metagenomic-based study of two sites from the Barbadian reef system

We study the microbiome of sea water collected from two locations of the Barbadian coral reefs. The two sites differ in several environmental and ecological variables including their endogenous benthic community and their proximity to urban development and runoffs from inland watersheds. The composition of the microbial communities was estimated using whole genome DNA shotgun sequencing with adjuvant measurements of chemical and environmental qualities. Although both sites exhibit a similar degree of richness, the less urbanized site (Maycocks reef at Hangman's Bay) has a strong concentration of phototrophs whereas the more urbanized location (Bellairs reef at Folkstone) is enriched for copiotrophs, macroalgal symbionts and marine-related disease-bearing organisms from taxa scattered across the tree of life. Our results are concordant with previous profiles of warm ocean surface waters, suggesting our approach captures the state of each coral reef site, setting the stage for longitudinal studies of marine microbiome dynamics in Barbados.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s00338-022-02330-y.

V-049 E-TEP RIVES-STOPPA AND OPEN REVERSE TRANVERSUS ABDOMINIS RELEASE (TAR): A HYBRID APPROACH FOR LARGE LATERAL-INFERIOR INCISIONAL HERNIAS

Aim

To present hybrid approach with open/endoscopic extraperitoneal dissection for large lateral-inferior incisional hernias

Material and Methods

64 years-old man who underwent left laparoscopic nephrectomy (2019) due to hypernephroma with specimen extraction by a left oblique iliac incision. He presents L3–4 W3 incisional hernia (14×10 cm)

Technique description

Results

After 48 hours ICU admission patient was discharged to hospital ward. Drainages were removed at 2nd-4thpostoperative day and hospital stay was 5 days.

Conclusion

The hybrid approach to large lateral incisional hernias allowed us to use a large sublay mesh with an increased overlap beyond the hernia defect, trying to reduce hernia recurrence rate.

P-100 ANATOMICAL STUDY ON THE PREPERITONEAL FAT DISTRIBUTION IN EXTENDED RETROMUSCULAR PREPERITONEAL DISSECTION: FROM THE FATTY TRIANGLE TO THE FATTY TRIDENT

Aim

Extended retromuscular dissection performed for abdominal wall reconstruction in complex abdominal wall repair has progressively exposed the anatomy between the peritoneal layer and abdominal wall muscles. This study aimed to assess the morphology and distribution of preperitoneal fat in a cadaveric model.

Material and methods

Thirty frozen cadaver torsos were dissected by posterior component separation. The shape of the preperitoneal fat was identified, and the dimensions and more significant distances were calculated.

Results

The results showed that the preperitoneal fat resembles a trident, exists along the midline under the linea alba, and expands in the epigastric area into a rhomboid shape. The fatty triangle was found to be a part of this rhomboid. The mean rhomboid area was 35 cm2. Caudally, the midline preperitoneal fat widened under the arcuate line to reach the Retzius space. Laterally, the Bogros space communicated the root of the trident with the paracolic gutters, Toldt's fascia, and pararenal fats, forming the lateral prong of the trident. The mean width of the midline prong at the umbilicus was 2.8 cm. It was easier to tear the peritoneum outside the area reinforced by the fatty trident.

Conclusions

The concept of preperitoneal fatty trident may be of practical assistance to perform various hernia procedures, from the simple ventral hernia repair to the more complex preperitoneal ventral repair or posterior component separation techniques. The consistency of this layer allows us to follow our plane between the peritoneum and muscle layers to extend the preperitoneal dissection.

V-018 PREOPERATIVE OPTIMIZATION AND POSTERIOR COMPONENT SEPARATION WITH INTRAOPERATIVE MONITORING OF RECTUS MUSCLE INERVATION FOR LOSS OF DOMAIN INCISIONAL HERNIA

Aim

The importance of an appropriate patient optimization (botulin toxin and pneumoperitoneum) and adequate surgical technique is highlighted.The possibility of intraoperative monitoring of the nerves that may be injured during posterior component separation is explained

Material and methods

We present a 74 years old man, past smoker, with history of hypertension, steatohepatitis and chronic bronchopathy

Results

This is a disastrous but unfortunately not so uncommon story of a failed repair of a simple umbilical hernia with 3 previous unsuccessful attempts of repair with and without mesh. After the last surgery the patient developed a giant incisional hernia with loss of domain. Optimization consisted of improving nutritional status, respiratory physiotherapy, botulin toxin and pneumoperitoneum. The surgery was made using previous skin scar. After dissecting the retrorectus space, a posterior component separation was made with the aid of monitoring the nerves that come to innervate the rectus abdominis. An overextended overlapped was obtained. A patch of absorbable mesh was used to completely close the peritoneum. A combination of absorbable and permanent synthetic mesh was used as giant reinforcement of the visceral sac. The only points of fixation were the Cooper Ligaments. The patient had a satisfactory recovery without complications and was discharged on the 8th postoperative day.

Conclusions

Loss of domain incisional hernias is a real surgical challenge. The combination of a good preoperative strategy (preoperative neumoperitoneum) and surgical technique (TAR and pannniculectomy) gives a great opportunity to solve very complex cases of incisional hernia.

V-007 LESSONS LEARNED DURING THE ABDOMINAL WALL RECONSUTRCTION FOR A MULTIRECURRENT LUMBAR HERNIA AFTER BONE GRAFT HARVESTING

The best approach for lateral incisional hernia is not known. Among these difficult hernias, those arising from iliac crest harvesting can be particularly challenging. The objective of this video is to illustrate the surgical approach of a multirecurrent case with the need of adding a posterior component separation

A 70 years old woman with 2 previous attempts of repair was referred to our center. With the patient in a 45 degrees lateral decubitus, a posterior lumbar approach was initiated through the previous scar. The retromuscular preperitoneal plane was accessed with difficulty due to previous meshes in the subdiaphragmatic, iliac and posterior areas. A big tear on the medial peritoneum changed our plan to add a posterior component separation. As we did not want to enlarge the lumbar incision to denervate more the lateral abdominal wall, we decided to make an accessory midline incision. Probably, an ETEP approach could have been better even before making the posterior incision. Once the retromuscular plane was dissected, the hole in the peritoneum could be closed. The reconstructive phase consisted in making a taco configuration using the combination of a permanent and absorbable mesh.

We have learned from this case, that an eTEP dissection of the retromuscular plane could have helped to avoid the accessory midline incision. It is also important to consider the potential iatrogenic denervation we could add in case of enlargement of the incision.

POS1493-HPR FACTORS ASSOCIATED WITH THE OCCURRENCE OF MENTAL DISORDERS IN PATIENTS WITH AUTOIMMUNE RHEUMATIC DISEASES DURING THE COVID-19 PANDEMIC

Background

Mental disorders constitute a serious and underestimated problem in Latin America and they could have worse features in comparison with Europe or North America (1); that was the case even before the COVID-19 epidemic ensued in 2020.

Objectives

The objective of this study was to determine the factors associated with the occurrence of mental health disorders (MHD) in patients with autoimmune rheumatic disease (ARD) from Perú, a high COVID-19 incidence country.

Methods

Patients with ARD from a single center (Hospital Guillermo Almenara -EsSalud, Lima-Perú) were included during the first and second waves of the COVID-19 pandemic (March to November 2020). Interviews, medical records reviews, and an electronic survey were performed. MHD explored were depression (assessed with the Patient Health Questionnaire 9: PHQ-9), anxiety (ascertained with the Generalized Anxiety Disorder-7: GAD-7) and post-traumatic stress disorder: PTSD (evaluated with the Event Scale-Revised: IES-R). Variables examined were sociodemographic (age, gender, educational level, marital status, living alone, job status, religiosity), previous diagnosis and treatment for mental disorders, living with a COVID-19 patient, COVID-19 diagnosis (current or past), fear of COVID-19 (assessed with the COVID-19 Scale: FCV-19S) and the ARD type. Multivariable logistic regression models using backward elimination procedure were performed to determine the variables associated with depression, anxiety, and PTSD. (See Table 1).

Table 1.

Variables associated with depression, anxiety an PSTD on ARD patients: Multivariable analysis.

DepressionAnxietyPTSDvariablesOR (CI=95%)p valueOR (CI95%)p valueOR (CI95%)p valuePrevious treatment for mental disorders2.35 (1.37-4.0)30.0022.42 (1.37-4.26)0.0022.42 1.39-4.210.002Fear for COVID-191.07 (1.05-1.10)<0.0011.09 (1.06-1.12)<0.0011.41 1.11-1.17<0.001COVID-19 diagnosisNSNS1.75 1.06-2.890.028Educational level University/postgraduate High SchoolNS0.43 (0.82-0.21)0.009NS ElementaryNS0.52 (0.28-0,95) Ref.0.032NSMarital status SingleNSNS0.57 (0.34-0.96)0.033 Divorced/separateNSNS1.02 (0.73-1.41)0.919

Results

Nine hundred and thirteen ARD patients were evaluated. The most frequent diagnosis was rheumatoid arthritis in 446(48.8%) patients followed by systemic lupus erythematosus in 279 (30.6%). Depression, anxiety, and PTSD were observed in 128 (14.0%), 112 (12.30%) and 485 (53.1%) patients, respectively. In the multivariable analyses, previous treatment for mental disorders and fear of COVID-19 were associated with depression: OR=2.35 (95% CI 1.37-4.03; p=0.002) and OR=1.07 (95% CI 1.05-1.10; p<0.001) respectively; also with anxiety: OR= 2.42 (95% CI 1.37-4.26; p=0.002) and OR=1.09 (95% CI 1.06-1.12; p <0.01) and with PSTD: OR=2.42 (95% CI 1.39-4.21;p=0.002) and OR=1.41 (95% CI=1.11-1.17; p<0.001). A diagnosis of COVID-19 was associated with PTSD: OR=1.75 (95% CI 1.06-2.89, p=0.028), while being single was associated with a decreased probability of PTSD occurrence: OR=0.57 (95% CI=0.35-0.96; p=0.03). Finally, having a high educational level was associated with less anxiety: OR=0.43 (95% CI=0.82-0.21; p=0.009), for university /postgraduate studies and OR=0.52 (CI 95%=0.28-0.95; p=0.032) for secondary studies.

Conclusion

Fear of COVID-19 and previous treatment for mental disorder were associated with all MHD explored on our ARD patients during the COVID-19 pandemic.

References

[1]Zhang S. Eur J Psychotraumatol. 2021;12(1):2001192.

Disclosure of Interests

None declared

High frequency of spin bias in controlled trials of cannabis derivatives and their synthetic analogues: A meta-epidemiologic study

OBJECTIVE

To investigate the frequency and perform a qualitative analysis of spin bias in publications of controlled trials assessing the therapeutic use of cannabis derivatives and their synthetic analogues.

STUDY DESIGN AND SETTING

Meta-epidemiologic study carried out at the Universidade Federal de São Paulo, Brazil.

RESULTS

A total of 65 publications with at least one efficacy primary outcome were considered. The results analysis for the primary outcome indicated statistically significant effects in 44.6% (29/65) of the publications, and 70.7% (45/65) of the conclusions were considered favorable to the intervention. Among the 36 publications that found statistically nonsignificant results for the primary outcome, 44.4% (16/36) presented conclusions favorable to or recommending the intervention, which represents spin bias according to the definition adopted in this study. Qualitative analysis of the 16 studies with spin bias showed selective outcomes reporting (elevating secondary outcomes that had positive results or reporting only subgroup results), deviations from the planned statistical analysis, and failure to consider or report uncertainty in the estimates of treatment effects.

CONCLUSION

The frequency of spin bias among publications of controlled trials with statistically nonsignificant results assessing the therapeutic use of cannabis derivatives and their synthetic analogues reached 44.4%. When not observed by readers, such deviation can lead to misconduct in clinical practice through the adoption of interventions that are not effective or whose effectiveness is uncertain.

Mussismilia braziliensis White Plague Disease Is Characterized by an Affected Coral Immune System and Dysbiosis

Infectious diseases are one of the major drivers of coral reef decline worldwide. White plague-like disease (WPL) is a widespread disease with a complex etiology that infects several coral species, including the Brazilian endemic species Mussismilia braziliensis. Gene expression profiles of healthy and WPL-affected M. braziliensis were analyzed in winter and summer seasons. The de novo assembly of the M. braziliensis transcriptome from healthy and white plague samples produced a reference transcriptome containing 119,088 transcripts. WPL-diseased samples were characterized by repression of immune system and cellular defense processes. Autophagy and cellular adhesion transcripts were also repressed in WPL samples, suggesting exhaustion of the coral host defenses. Seasonal variation leads to plasticity in transcription with upregulation of intracellular signal transduction, apoptosis regulation, and oocyte development in the summer. Analysis of the active bacterial rRNA indicated that Pantoea bacteria were more abundant in WPL corals, while Tistlia, Fulvivirga, and Gammaproteobacteria Ga0077536 were more abundant in healthy samples. Cyanobacteria proliferation was also observed in WPL, mostly in the winter. These results indicate a scenario of dysbiosis in WPL-affected M. braziliensis, with the loss of potentially symbiotic bacteria and proliferation of opportunistic microbes after the start of the infection process.

Feasibility, tolerability, and safety of hysterosalpingo-foam sonography (hyfosy). multicenter, prospective Spanish study

OBJECTIVE

To determine the feasibility,tolerability, and safety of the ultrasound assessment of tubal patency using foam as contrast.

METHODS

This was a prospective multicenter study of 915 infertile nulliparous women scheduled for sonohysterosalpingography with foam instillation (HYFOSY) for tubal patency testing as a part of the fertility workup. Clinical and sonographic data were recorded into a web-shared database. Tubal patency, cervical catheterization, pain during the procedure and post-procedural complications were collected. Patients reported discomfort or pain experienced during the procedure with a visual analogue scale (VAS) score.

RESULTS

Nine hundred fifteen women were included in the final analysis. Median age was 34 (range, 21-45) years and median body mass index was 23 (range, 16-41) kg/m2. Of 839 women, only 8(0.95 %) cases were abandoned due to impossibility of introducing the intracervical catheter. Most of the cervical os were easily cannulated with either paediatric nasogastric probes or special catheter for intrauterine insemination / sonohysterosalpingography 688/914(75.3 %). With a median instillation of 4 mL (range 1-16) of foam, both tubes were identified in 649/875 (70.9 %) patients, while unilateral patency was observed in 190/875 (20.8 %). Only 36/875 (3.9 %) of the women had bilateral tubal obstruction. The median VAS score for perception of pain during HyFoSy examination was 2 (range 0-10), and only 17 (1.9 %) of women reported severe pain (VAS ≥ 7). Pain was unrelated to tubal patency or tubal blockage. Unexpectedly, difficult cervical catheterizations that needed tenaculum, were more likely associated with mild pain during procedure [nasogastric probe group 176/289 (70.9 %) vs. insemination catheter group 166/399 (41.6 %) vs. tenaculum group 190/218(87.2 %) p < 0.001]. Finally, among 915 patients, we only noticed 3 (0.32 %) complications of the technique: two vasovagal episodes and a mild urinary infection.

CONCLUSION

HYFOSY is a feasible, well-tolerated and safe technique for the evaluation of tubal patency in infertile women.

Malmström vacuum or Kielland forceps: which causes more damage to pelvic floor?

OBJECTIVE

To determine whether differences exist in the rate of levator ani muscle (LAM) avulsion between women who had undergone either Malmström vacuum delivery (MVD) or Kielland forceps delivery (KFD), allowing for potential confounding factors.

METHODS

This was a prospective observational study of nulliparous women undergoing instrumental delivery using Malmström vacuum extractor or Kielland forceps, at two hospital centers in Spain. Fetal head position (anterior, posterior or transverse) and fetal head station (low or mid) were assessed by ultrasound and digital examination, respectively. Avulsion was defined on tomographic ultrasound imaging as an abnormal insertion of the LAM in the three central slices from the plane of minimal hiatal dimensions.

RESULTS

In total, 414 patients were included in the study (212 MVD and 202 KFD). We observed a higher rate of LAM avulsion in the KFD group (KFD 49.5% vs MVD 32.5%; P = 0.001). When the results were evaluated according to fetal head position and station, we observed no differences in LAM avulsion. The crude odds ratio (OR) for the difference in avulsion between women in the KFD and MVD groups was 2.03 (95% CI, 1.36-3.03). However, when adjusted for duration of second stage of labor, fetal head circumference and fetal head station, the OR was no longer statistically significant (OR, 2.14 (95% CI, 0.95-4.85); P = 0.068).

CONCLUSION

When potential confounding factors are taken into account, the rate of LAM avulsion does not differ between women according to whether they have undergone KFD or MVD. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Remission and low disease activity state prevent hospitalizations in systemic lupus erythematosus patients

OBJECTIVE

The aim of this study was to determine whether remission and low disease activity state protect systemic lupus erythematosus patients from being hospitalized.

MATERIALS AND METHODS

Patients from the Almenara Lupus Cohort were included. Visits were performed every 6 months. Variables were measured at each visit. Hospitalizations were evaluated in the interval between two visits. Remission was defined as: a SLEDAI-2 K of 0, prednisone ≤5 mg/day and immunosuppressants on maintenance dose; low disease activity state as: a SLEDAI-2 K of ≤4, prednisone ≤7.5 mg/day and immunosuppressants on maintenance dose. Univariable and multivariable interval-censored survival regression models were used. In multivariable analysis, possible confounders were gender, age at diagnosis, socioeconomic status, educational level, disease duration, antimalarial use, the Systemic Lupus International Collaborating Clinics/American College of Rheumatology damage index (SDI) and Charlson comorbidity index. Confounders were determined in the same visit as disease activity state.

RESULTS

Of the 308 patients, 92.5% of them (n = 285) were women, had a mean age at diagnosis of 34.8 (13.4) years and a disease duration of 7.7 (6.5) years. At baseline the mean SDI was 1.13 (1.34). A total of 163 of the patients were hospitalized. In the multivariable analysis remission (hazard ratio 0.445 (0.274-0.725), P = 0.001) and low disease activity state (relative risk 0.504 (0.336-0.757), P = 0.001) at baseline were found to decrease the risk of hospitalization in systemic lupus erythematosus patients. A total of 158 hospitalizations presented a discernible cause. Disease activity was the most common cause of hospitalization, with 84 admissions (53.16%), the majority, 38, was due to active kidney disease (45.23%).

CONCLUSION

Remission and low disease activity state decreased the risk of hospitalizations in these systemic lupus erythematosus patients. Disease activity, particularly renal, was the most frequent cause of hospitalization.

Lactobacillus casei CRL 431 improves endothelial and platelet functionality in a pneumococcal infection model

Streptococcus pneumoniae is able to activate coagulation and induce platelet aggregation, both of which are typical responses to systemic inflammation. The interactions between inflammation and coagulation and between soluble adhesion molecules and endothelial cells are important in the pathogenesis of an unbalanced haemostatic system. Therefore, an exaggerated and/or insufficiently controlled haemostatic activity may appreciably contribute to the severity of the disease. The aim of the present study was to evaluate the effect of the oral administration of Lactobacillus casei CRL 431 on platelet and endothelial activation mechanisms in a respiratory pneumococcal infection model in mice. S. pneumoniae induced an increase in platelet counts and enhanced the expression of P-selectin in control group, with higher endothelial activation in lung shown by the increase in von Willebrand factor (vWF) and vascular cell adhesion molecule 1 (VCAM-1) expression. Also, infection induced a decrease in CXCR-4 leukocytes, increased expression in annexinV and cell death at the pulmonary level and decreased antithrombin levels in bronchoalveolar lavage. In contrast, L. casei mice restored platelet counts, favoured faster P-selectin expression, lower vWF levels and VCAM-1 expression than control group. Also, L. casei induced higher levels of annexinV expression and lower cell death in the lung. Moreover, it was able to modulate antithrombin levels within the normal range, which would indicate lower coagulation activation and a protective effect locally exerted by L. casei. In this work, the ability of L. casei to favourably modulate platelet and endothelial functionality during a pulmonary infection with S. pneumoniae was demonstrated. Our findings offer a promising perspective for the use of this probiotic strain in the prevention of thrombotic complications associated with pneumococcal pneumonia, especially in at-risk patients. In addition, the use of L. casei would provide novel alternatives for the prevention and treatment of thrombosis associated with various diseases.

Evaluation of the Normal Cochlear Second Interscalar Ridge Angle and Depth on 3D T2-Weighted Images: A Tool for the Diagnosis of Scala Communis and Incomplete Partition Type II

BACKGROUND AND PURPOSE

Cochlear malformations may be be subtle on imaging studies. The purpose of this study was to evaluate the angle and depth of the lateral second interscalar ridge or notch in ears without sensorineural hearing loss (normal ears) and compare them with ears that have a documented incomplete type II partition malformation.

MATERIALS AND METHODS

The second interscalar ridge notch angle and depth were measured on MR imaging in normal ears by a single experienced neuroradiologist. The images of normal and incomplete partition II malformation ears were then randomly mixed for 2 novice evaluators to measure both the second interscalar ridge notch angle and depth in a blinded manner. For the mixed group, interobserver agreement was calculated, normal and abnormal ear measurements were compared, and receiver operating characteristic curves were generated.

RESULTS

The 94 normal ears had a mean second interscalar ridge angle of 80.86° ± 11.4° and depth of 0.54 ± 0.14 mm with the 98th percentile for an angle of 101° and a depth of 0.3 mm. In the mixed group, agreement between the 2 readers was excellent, with significant differences for angle and depth found between normal and incomplete partition type II ears for angle and depth on average (P < .001). Receiver operating characteristic cutoffs for delineating normal from abnormal ears were similar for both readers (depth, 0.31/0.34 mm; angle, 114°/104°).

CONCLUSIONS

A measured angle of >114° and a depth of the second interscalar ridge notch of ≤0.31 mm suggest the diagnosis of incomplete partition type II malformation and scala communis. These measurements can be accurately made by novice readers.