Effects of inertia on conformation and dynamics of active filaments

Many macroscopic active systems such as snakes, birds and fishes have flexible shapes and inertial effects on their motion, in contrast to their microscopic counterparts, cannot be ignored. Nonetheless, the consequences of interplay between inertia and flexibility on their shapes and dynamics remain unexplored. Here, we examine inertial effects on the most studied active flexible system, {\it i.e.} linear active filaments pertinent to worms, snakes and filamentous robots. Performing Langevin dynamics simulations of active polymers with underdamped and overdamped dynamics for a wide range of contour lengths and activities, we uncover striking inertial effects on their conformation and dynamics. Inertial collisions increase the persistence length of active polymers and remarkably alter their scaling behavior. In stark contrast to passive polymers, inertia leaves its fingerprint at long times by an enhanced diffusion of the center of mass. We rationalize inertia-induced enhanced dynamics by analytical calculations of center of mass velocity correlations, revealing significant contributions from active force fluctuations convoluted by inertial relaxation.Comment: 5 pages, 4 figure

Cone-Beam Computed Tomography Comparison of Canal Transportation after Preparation with BioRaCe and Mtwo Rotary Instruments and Hand K-Flexofiles

Introduction: The aim of this in vitro study was to evaluate the transportation of mesiobuccal canals of mandibular first molars prepared with either BioRaCe or Mtwo rotary instruments or hand K-Flexofile, by means of cone-beam computed tomography (CBCT). Methods and Materials: Forty-five mandibular molars were selected and randomly divided into three groups (n=15). Mesiobuccal roots of these teeth were prepared by BioRaCe, Mtwo, or hand K-Flexofile. Transportation was measured by pre- and post-operative CBCT images. Two-way ANOVA analysis was applied to detect any differences between the groups followed by the post hoc Tukey’s tests. The level of significance was set at 0.05. Results: The non-parametric Friedman test was used to compare the behavior of each file at 3-, 6- and 9-mm levels. There were no significant differences between different levels in Mtwo group (P=0.15); however, the differences in K-Flexofile and BioRaCe groups were significant (P>0.05). Post hoc Tukey’s test revealed significant differences between BioRaCe and K-Flexofile and also between Mtwo and K-Flexofile, both in the 3-mm depths (P<0.05). Conclusion: Under the limitations of the present study, BioRaCe and Mtwo rotary instruments are considered suitable for canal preparation to greater apical sizes provided that the recommended sequences are observed

An Upgrade Pinning Block: A Mechanical Practical Aid for Fast Labelling of the Insect Specimens

A new mechanical innovation is described to deal with standard labelling of dried specimens on triangular cards and/or pinned specimens in personal and public collections. It works quickly, precisely, and easily and is very useful for maintaining label uniformity in collections. The tools accurately sets the position of labels in the shortest possible time. This tools has advantages including rapid processing, cost effectiveness, light weight, and high accuracy, compared to conventional methods. It is fully customisable, compact, and does not require specialist equipment to assemble. Conventional methods generally require locating holes on the pinning block surface when labelling with a resulting risk to damage of the specimens. Insects of different orders can be labelled by this simple and effective tool

The Probable Effect of Irrigation Solution and Time on Bond Strength to Coronal Dentin: An In Vitro Evaluation

Introduction: The aim of this study was to evaluate the effect of root canal irrigants on the microtensile bond strength of 2-step self-etch adhesive to dentin. Methods and Materials: In this study 36 sound extracted human third molars were used. After grinding 3 mm of occlusal surface, teeth were randomly divided into 6 groups based on irrigation material naming normal saline, 5.25% sodium hypochlorite (NaOCl) and 2% chlorhexidine (CHX) and also irrigation time (5 or 30 min). Next, teeth were restored with Clearfil SE bond adhesive resin system and Z250 composite. The teeth were then thermo cycled by thermo cycling machine, for 500 cycles between 5º and 55ºC with 60 sec dwell time and 12 sec transfer time. All samples were sectioned into bucco-lingual slabs. The sections were submitted to the micro tensile testing machine at a crosshead speed of 0.5 mm/min until fracture. Data was analyzed using the one-way ANOVA test with the level of significance set at 0.05. Results: Irrigation with normal saline, 5.25% NaOCl and 2% CHX for 5 or 30 min did not significantly change the microtensile bond strength of adhesive to dentin (P=0.729 for time and P=0.153 for material). However the maximum and minimum microtensile bond strength was attributed to normal saline (44.13 N) and NaOCl (31.29 N) groups, respectively. Conclusion: Iirrigation solution and time have no influence on microtensile bond strength of two-step self-etch adhesive to coronal dentin.Keywords: Bond Strength, Dentin, Irrigation Solution

Active motion of tangentially driven polymers in periodic array of obstacles

One key question about transport of active polymers within crowded environments is how spatial order of obstacles influences their conformation and dynamics when compared to disordered media. To this end, we computationally investigate the active transport of tangentially driven polymers with varying degrees of flexibility and activity in two-dimensional square lattices of obstacles. Tight periodic confinement induces notable conformational changes and distinct modes of transport for flexible and stiff active filaments. It leads to caging of low activity flexible polymers inside the inter-obstacle pores while promoting more elongated conformations and enhanced diffusion for stiff polymers at low to moderate activity levels. The migration of flexible active polymers occurs via hopping events, where they unfold to move from one cage to another, similar to their transport in disordered media. However, in ordered media, polymers are more compact and their long-time dynamics is significantly slower. In contrast, stiff chains travel mainly in straight paths within periodic inter-obstacle channels while occasionally changing their direction of motion. This mode of transport is unique to periodic environment and leads to more extended conformation and substantially enhanced long-time dynamics of stiff filaments with low to moderate activity levels compared to disordered media. At high active forces, polymers overcome confinement effects and move through inter-obstacle pores just as swiftly as in open spaces, regardless of the spatial arrangement of obstacles. We explain the center of mass dynamics of semiflexible polymers in terms of active force and obstacle packing fraction by developing an approximate analytical theory

The subfamily Pteromalinae (Chalcidoidea: Pteromalidae) in South-Eastern Iran

A faunistic survey on the parasitic wasps of the subfamily Pteromalinae Dalman, 1820 (Hym., Chalcidoidea, Pteromalidae) of South-Eastern Iran (Kerman province) was done. In total 46 specimens representing 10 genera and 16 species are identified, among them, Dinarmus altifrons (Walker, 1862) and Syntomopus incurvus Walker, 1833 are recorded for the first time for the fauna of Iran. Previously recorded species of Pteromalinae from this area are also reviewed and listed. Faunistic analysis of the known species according to their distribution both in Iran and in a broader biogeographical sense is also discussed

APHIDS (HEMIPTERA: APHIDIDAE) ASSOCIATED WITH GRASSLANDS OF CENTRAL ALBORZ, IRAN

The aphid fauna associated with various host plants in grassland areas of central Alborz in Iran were studied. The samples were collected from 2002-2010 from different locations  in the southern foothills of  the Alborz Mountains which are a major highland on  the plateau of Iran. Eighty aphid species from 32 genera in association with 168 host plants were collected and identified.  In all, 284 aphid-host plant associations were recorded, 112 of which are new to Iran. Our results showed that grassland areas of central Alborz could be considered as major refugia for aphids from where they migrate to the neighboring cultivated fields. The aphid fauna associated with various host plants in grassland areas of central Alborz in Iran were studied. The samples were collected from 2002-2010 from different locations  in the southern foothills of  the Alborz Mountains which are a major highland on  the plateau of Iran. Eighty aphid species from 32 genera in association with 168 host plants were collected and identified.  In all, 284 aphid-host plant associations were recorded, 112 of which are new to Iran. Our results showed that grassland areas of central Alborz could be considered as major refugia for aphids from where they migrate to the neighboring cultivated fields

Correlation of Preoperative and Radical Prostatectomy Gleason Score: Examining the Predictors of Upgrade and Downgrade Results

Preoperative Gleason score (GS) obtained from Trans Rectal Ultra Sonography (TRUS) is the most common grading system to evaluate the appropriate treatment for patients with clinically localized prostate cancer. But this method showed upgraded and downgraded results in comparison to Gleason score obtained from radical prostatectomy. The current study aimed to determine clinical or pathological variables to reduce the differences between biopsy and radical prostatectomy Gleason scores.Through retrospective review of 52 patients with radical prostatectomy, this study examined the correlations of preoperative Gleason score with age, prostate volume, PSA level, PSA density, digital rectal exam findings and percentage of positive core needle biopsies across two groups, including patients with preoperative GS≤6 (i.e. group one) and patients with preoperative GS≥7 (group two). The discordance between biopsy GS and radical prostatectomy GS was observed to be 52% in the current study. Among patients with preoperative GS≤6, prostate volume (P=0.026), PSA density (P=0.032) and percentage of positive core needle biopsies (P=0.042) were found to be significant predictors for upgrade. There was no significant predictor for downgrade in patients with preoperative GS≥7. Findings of this study revealed that in patients with preoperative GS≤6, smaller prostate volume, higher prostate density and higher positive results of core needle biopsies were associated with theupgrade of GS. Therefore, it should be considered when selecting treatment modalities among these patients

Fertility Rate and Sperm DNA Fragmentation Index following Varicocelectomy in Primary Infertile Men with Clinical Varicocele: A Prospective Longitudinal Study

Background: Varicocele is one of the most common treatable causes of male infertility, and its treatment may bebeneficial for fertility. This study aimed to evaluate fertility rate and DNA fragmentation index (DFI) following varicocelectomyin primary infertile men with clinical varicocele.Materials and Methods: This prospective longitudinal study was conducted on primary infertility men, in a tertiarycenter from December 2018 to December 2019 with one-year follow-up. Data of the semen parameters, DFI (%), andfertility rate were gathered before, as well as 4 and 12 months after undergoing varicocelectomy. For data analysis,SPSS software and analytical test were used.Results: Out of 76 patients who were analyzed, 22 (29%) became fertile and 54 (71%) remained infertile. Semenparameters and DFI (%) were improved significantly following varicocelectomy (P<0.001). Smoking history, occupationalheated exposure, body mass index (BMI), and infertility duration were determined as predictors associatedwith fertility status (P<0.05).Conclusion: Although varicocele repair improved the DFI, the fertility rate was achieved in less than one-third ofpatients; it seems that the other parameters, such as the history of smoking, occupational heated exposure, overweight,and duration of infertility should be considered as predictors of fertility status, in primary infertile men who are a candidatefor varicocelectomy

Global, regional, and national burden of colorectal cancer and its risk factors, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019

Funding: F Carvalho and E Fernandes acknowledge support from Fundação para a Ciência e a Tecnologia, I.P. (FCT), in the scope of the project UIDP/04378/2020 and UIDB/04378/2020 of the Research Unit on Applied Molecular Biosciences UCIBIO and the project LA/P/0140/2020 of the Associate Laboratory Institute for Health and Bioeconomy i4HB; FCT/MCTES through the project UIDB/50006/2020. J Conde acknowledges the European Research Council Starting Grant (ERC-StG-2019-848325). V M Costa acknowledges the grant SFRH/BHD/110001/2015, received by Portuguese national funds through Fundação para a Ciência e Tecnologia (FCT), IP, under the Norma Transitória DL57/2016/CP1334/CT0006.proofepub_ahead_of_prin