Study of regularities of anatomical shape of eyeball at weak zinn support in patients with senile uncomplicated cataract

As experience shows, periodically after the planned cataract surgery with the implantation of an intraocular lens (IOL) into the capsule bag and uncomplicated course of the early postoperative period, there are cases of spontaneous dislocation of the "IOL – capsule bag" complex later. Their frequency is 0.2–2.8% of all cases of IOL dislocations. This is due to the initial weakness of the fibers of the zonule of Zinn, which was not detected during the preoperative examination. Purpose. To study the variants of the anatomical shape of the eyeball in patients with weak of the zonule of Zinn. Material and methods. The clinical material is presented by 30 patients with senile cataracts. Their ages ranged from 53 to 75 years old. The main group consisted of 15 patients with 1st degree lens subluxation. The comparison group included 15 patients without signs of weakness in zonule of Zinn support. The anatomical shape of the eyeball was evaluated. For this, the anteroposterior axis (APA) and transverse axis (TA) of the eyeball were measured, followed by calculation of the variant of the anatomical shape of the eye, using the assessment of options for the APA / TA ratio. Results. When using a comparative assessment of the values of the ratio APA / TA, a statistically significant difference between the groups of 1.10±0.04 versus 1.05±0.05 was revealed (Student's t test, p = 0.004). This indicates that the shape of the eyes in the form of a more elongated ellipsoid prevailed statistically significantly in the main group. Conclusion. The data obtained indicate an objective tendency towards the predominance of the anatomical shape of the eye in the form of a more elongated ellipsoid. It is possible that this fact is of clinical significance for the development of weakness of the zonule of Zinn support in the main group. Key words: the zonule of Zinn, weakness of the zonule of Zinn support, senile cataract, anatomical shape of the eye, anteroposterior axis of the eye, transverse axis of the eye.

Proximal CA3 is the primary locus of age-related pattern separation deficits in rats

Age-related deficits in pattern separation have been postulated to bias the output of hippocampal memory processing toward pattern completion, which can cause deficits in accurate memory retrieval. While the CA3 region of the hippocampus is often conceptualized as a homogeneous network involved in pattern completion, growing evidence demonstrates a functional gradient in CA3 along the transverse axis, with proximal CA3 supporting pattern separation and distal CA3 supporting pattern completion. We examined the neural representations along the CA3 transverse axis in young (Y), aged memory-unimpaired (AU), and aged memory-impaired (AI) rats when different changes were made to the environment. When the environmental similarity was high (e.g., altered cues or altered environment shapes in the same room), Y and AU rats showed more orthogonalized representations in proximal CA3 than in distal CA3, consistent with prior studies showing a functional dissociation along the transverse axis of CA3. In contrast, AI rats showed less orthogonalization in proximal CA3 than Y and AU rats but showed more normal (i.e., generalized) representations in distal CA3, with little evidence of a functional gradient. When the environmental similarity was low (e.g., recordings were done in different rooms), representations in proximal and distal CA3 remapped in all rats, showing that AI rats are able to dissociate representations when inputs show greater dissimilarity. These results provide evidence that the aged-related bias towards pattern completion is due to the loss in AI rats of the normal transition from pattern separation to pattern completion along the CA3 transverse axis and, furthermore, that proximal CA3 is the primary locus of this age-related dysfunction in neural coding.

The Nobel Laureate Georg von Békésy’s Hearing Theory

After Békésy the stapes base moves around two axes: for weaker sounds - rotates around its transverse axis; in case of a strong sound - it moves around its longitudinal axis. Békésy’s place theory cannot alone explain the frequency-distinguishing ability of the ear. However, the existence of active amplification further sharpens the frequency-analysing ability of the cochlea. In addition, the different frequency sensitivity of afferent nerve fibres of inner hair cells synergizes with the mechanisms above. Peaked resonance curves are consequences of different threshold sensitivities of nerves connecting to individual hair cells. The frequency, which belongs to the lowest stimulus threshold, is called the characteristic frequency of a nerve. This place assignment of nerve frequencies are formed by the following mechanism in the cochlea. The place of amplitude maxima of progressive waves excited in the basilar membrane shows slight frequency dependence. The mechanism of active amplification forming in outer hair cells amplifies and sharpens the resonances of the basilar membrane. In 1961, nobleman Georg von Békésy received the Nobel Prize in Medicine: “for his discoveries of the physical mechanisms of stimulation within the cochlea”.

Preliminary Outcomes of Viabahn Balloon-Expandable Endoprosthesis as Bridging Stent in Renal Arteries During Fenestrated Endovascular Aortic Repair

Purpose: To report preliminary outcomes of Viabahn Balloon-Expandable Endoprosthesis (VBX) stent-graft as bridging stent for renal arteries in fenestrated endovascular aneurysm repair (FEVAR). Materials and Methods: Between 2018 and 2019, patients undergoing FEVAR at 3 referral Italian university hospitals were prospectively collected. During the study period, VBX was the first-line choice as bridging stent for renal arteries. Procedural and anatomical data were analyzed, including renal artery (RA) configuration. A dedicated software (3Mensio, Vascular Imaging, Bilthoeven, The Netherlands) was used and RA anatomy classified as follow: upward-oriented in case of any angle >30° above the horizontal or transverse axis perpendicular to the aortic axis, downward-oriented if there was an angle >30° measured below the transverse axis and downward + upward in case of an angle <30° associated with a renal artery angulation >90°. Primary endpoints were technical success, defined as complete deployment of the fenestrated endograft without target vessel (TV) loss, limb stenosis or occlusion and type I or III endoleak, and freedom from target artery instability (TAI), defined by target vessel-related death, occlusion, rupture or reintervention for stenosis, endoleak or disconnection. Secondary endpoints were target artery patency rate and freedom from reinterventions. Results: A total of 26 elective FEVAR for juxta/pararenal aneurysm (20), thoracoabdominal type II (3) and type IV (3) were included. Fifty-one RA were planned for revascularization. Of these, 32 were downward, 10 horizontal, 6 upward, 4 were downward + upward. Technical success was achieved in 88.5% (23/26) of patients and 94.2% (48/51) of the TVs. One occlusion (2.1%) occurred within 30 days in a patient with previous endovascular aortic repair and suprarenal fixation. During follow-up (median 10 months), there was 1 type IC endoleak after 6 months (2.1%) in a patient with upward plus downward arterial orientation. Freedom from TAI was 96.1% (CI = 0.89 to 1.04) at first month and 92.3% (CI = 0.82 to 1.03) at 6 months. No aneurysm-related mortality and renal insufficiency occurred during follow-up. Conclusion: The use of VBX as bridging stent of RA in FEVAR is safe and feasible. Previous EVAR and tortuosity of RA may be a challenging on target vessel fate.

Models for predicting the performance of fertilizer metering in seed cum fertilizer drill

ABSTRACT This study aimed to establish mathematical models that predict the performance of helical fertilizer metering according to the longitudinal and transverse inclinations, angular speed, and helical pitch. Laboratory tests were carried out with helical meterings with lateral and longitudinal discharge through overflow and with two helicoids, working at an angular speed of 16 and 46 rpm at the following longitudinal inclination angles: -20, -15, -10, -5, 0, +5, +10, +15, and +20° and on the transverse axis: -15, -10, -5, 0, +5, +10, and +15°. It was found that the variation of the transverse inclination has little effect on the dosage. When using fertilizer metering with a helicoid, the higher the longitudinal inclination, the greater the dosage in a linear manner, while the meterings with two helicoids provided less oscillation of the dosages according to the inclinations.

Gold Nanopeanuts as Prospective Support for Cisplatin in Glioblastoma Nano-Chemo-Radiotherapy

Herein, we propose newly designed and synthesized gold nanopeanuts (Au NPes) as supports for cisplatin (cPt) immobilization, dedicated to combined glioblastoma nano-chemo-radiotherapy. Au NPes offer a large active surface, which can be used for drugs immobilization. Transmission electron microscopy (TEM) revealed that the size of the synthesized Au NPes along the longitudinal axis is ~60 nm, while along the transverse axis ~20 nm. Raman, thermogravimetric analysis (TGA) and differential scanning calorimetry (DCS) measurements showed, that the created nanosystem is stable up to a temperature of 110 °C. MTT assay revealed, that the highest cell mortality was observed for cell lines subjected to nano-chemo-radiotherapy (20–55%). Hence, Au NPes with immobilized cPt (cPt@AuNPes) are a promising nanosystem to improve the therapeutic efficiency of combined nano-chemo-radiotherapy.

Applied anatomical study on suprascapular nerve protection in reverse total shoulder arthroplasty

Background This study aimed to investigate the three-dimensional (3D) anatomical relationship between the suprascapular nerve and scapula, and the method of protecting the suprascapular nerve in reverse total shoulder arthroplasty (RTSA) Methods In the present study, 12 fresh adult cadaver shoulder specimens were dissected. X-ray and computed tomography (CT) were used to investigate the 3D scapular and suprascapular nerve images. Results The results revealed that the best fitting baseplate diameter was 24.73 ± 1.56 mm. Furthermore, the baseplate diameter correlated with the glenoid cavity width. After the osteotomy, a simulated screw placement on the baseplate was performed. The dangerous area for the posterior screw placement was at the angle between the upper edge and transverse axis exceeding 38° and between the lower edge and transverse axis exceeding 76°. The distance between the nearest point of the nerve and osteotomy plane was 15.38 ± 2.02 mm, and the angle between the projection point of the nearest point and transverse axis was 27.33 ± 7.96°, which was the dangerous area for retractor placement. The suitable angle between the superior screw and longitudinal axis was 21.67 ± 13.27°, and the suitable superior screw length was 34.66 ± 2.41 mm. Conclusion In RTSA, the baseplate size correlates with the glenoid cavity width. The relationship between the screw and suprascapular nerve and retractor placement position should be carefully considered to avoid damaging the suprascapular nerve.

Distal CA1 maintains a more coherent spatial representation than proximal CA1 when local and global cues conflict

Entorhinal cortical projections show segregation along the transverse axis of CA1, with the medial entorhinal cortex (MEC) sending denser projections to proximal CA1 (pCA1) and the lateral entorhinal cortex (LEC) sending denser projections to distal CA1 (dCA1). Previous studies have reported functional segregation along the transverse axis of CA1 correlated with the functional differences in MEC and LEC. pCA1 shows higher spatial selectivity than dCA1 in these studies. We employ a double rotation paradigm, which creates an explicit conflict between local and global cues, to understand differential contributions of these reference frames to the spatial code in pCA1 and dCA1. We show that pCA1 and dCA1 respond differently to this local-global cue conflict. pCA1 shows incoherent response consistent with the strong conflicting inputs it receives from MEC and distal CA3 (dCA3). In contrast, dCA1 shows a more coherent rotation with global cues. In addition, pCA1 and dCA1 display comparable levels of spatial selectivity in this study. This finding differs from the previous studies, perhaps due to richer sensory information available in our behavior arena. Together these observations indicate that the functional segregation along proximodistal axis of CA1 is not merely of the amount of spatial selectivity but that of the nature of the different inputs utilized to create and anchor spatial representations.