To save content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about saving content to .
To save content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
The Jurassic rocks of Gebel Maghara, northern Sinai, Egypt, contain a well-preserved and highly diverse macrobenthic fauna, dominated by bivalves. This fauna, particularly bivalves and gastropods, have received little attention in the last 100 years. In an attempt to provide a sound database on the marine bivalve diversity of Egypt during the Jurassic period, a first faunal group, the protobranch bivalves, is reviewed in detail. Sixteen taxa (three of them new), belonging to two orders, five families, and nine genera are systematically described and compared to closely related Jurassic taxa from various locations, particularly in Europe and India. New species are Nuculoma douvillei n. sp., N. sinaiensis n. sp., and Palaeoneilo aegyptiaca n. sp. In addition, Palaeonucula cuneiformis (J. de C. Sowerby), P. muensteri (Goldfuss), Dacryomya diana (d'Orbigny), D. lacryma (J. de. C. Sowerby), and Praesaccella juriana Cox are identified from Jurassic strata of Egypt for the first time. The younger records of the genus Palaeoneilo have not been accepted by some researchers, since almost all exhibit only limited features. The genus occurs with certainty in the Middle Jurassic (Bajocian‒Bathonian) rocks of Egypt, based on well-preserved external and internal characters. Similarly, Dacryomya and Ryderia from Bathonian‒Kimmeridgian rocks of Egypt are younger than previously recorded from other parts of the world. The identified genera have wide geographic ranges and have been reported from different faunal provinces, which suggests that latitudinal climate differences did not influence their distribution pattern to a great extent.
Background: Neuromodulation unit placement can provide efficacious control of many neurological conditions. They are high risk for infection with a historic infection rate as high as 10%. Treatment of infection requires surgical removal and a long course of systemic antibiotics. <font size=”1”> </font>At our center, one surgeon uses antibacterial envelopes with all implanted neuromodulation devices. Methods: We conducted a retrospective cohort study of consecutive implantable pulse generator (IPG) and intrathecal pump unit implantation with an antibacterial envelope at our center. This cohort was then compared to a historical cohort of consecutive patients undergoing IPG or pump placement or revision prior to the use of the envelopes. Results: IPG: There were 18 (11.9%) class I infections in the pre-envelope cohort compared with 5 (2.1%) in the post-envelope cohort. The absolute risk reduction (ARR) with the use of antibacterial envelopes was 9.85% (95% confidence interval (CI) 4.3-15.4%, p<0.01).
Pump: There were 6 (14.6%) class I infections in the pre-envelope cohort compared with 1 (1.7%) in the post-envelope cohort. The ARR with the use of antibacterial envelopes was 12.9% (95% confidence interval 1.6-24.3, p<0.05). Conclusions: Based on our results, we recommend usage of antibacterial envelopes to reduce infection rates in neuromodulation surgery. Further study is needed.
Few prospective studies have documented the seropositivity among those children infected with severe acute respiratory syndrome coronavirus 2. From 2 April 2021 to 24 June 2021, we prospectively enrolled children between the ages of 2 and 17 years at three North Carolina healthcare systems. Participants received at least four at-home serological tests detecting the presence of antibodies against, but not differentiating between, the nucleocapsid or spike antigen. A total of 1,058 participants were enrolled in the study, completing 2,709 tests between 1 May 2021 and 31 October 2021. Using multilevel regression with poststratification techniques and considering our assay sensitivity and sensitivity, we estimated that the seroprevalence of infection-induced antibodies among unvaccinated children and adolescents aged 2–17 years in North Carolina increased from 15.2% (95% credible interval, CrI 9.0–22.0) in May 2021 to 54.1% (95% CrI 46.7–61.1) by October 2021, indicating an average infection-to-reported-case ratio of 5. A rapid rise in seropositivity was most pronounced in those unvaccinated children aged 12–17 years, based on our estimates. This study underlines the utility of serial, serological testing to inform a broader understanding of the regional immune landscape and spread of infection.
The interaction of relativistically intense lasers with opaque targets represents a highly non-linear, multi-dimensional parameter space. This limits the utility of sequential 1D scanning of experimental parameters for the optimization of secondary radiation, although to-date this has been the accepted methodology due to low data acquisition rates. High repetition-rate (HRR) lasers augmented by machine learning present a valuable opportunity for efficient source optimization. Here, an automated, HRR-compatible system produced high-fidelity parameter scans, revealing the influence of laser intensity on target pre-heating and proton generation. A closed-loop Bayesian optimization of maximum proton energy, through control of the laser wavefront and target position, produced proton beams with equivalent maximum energy to manually optimized laser pulses but using only 60% of the laser energy. This demonstration of automated optimization of laser-driven proton beams is a crucial step towards deeper physical insight and the construction of future radiation sources.
We present the development and characterization of a high-stability, multi-material, multi-thickness tape-drive target for laser-driven acceleration at repetition rates of up to 100 Hz. The tape surface position was measured to be stable on the sub-micrometre scale, compatible with the high-numerical aperture focusing geometries required to achieve relativistic intensity interactions with the pulse energy available in current multi-Hz and near-future higher repetition-rate lasers (
kHz). Long-term drift was characterized at 100 Hz demonstrating suitability for operation over extended periods. The target was continuously operated at up to 5 Hz in a recent experiment for 70,000 shots without intervention by the experimental team, with the exception of tape replacement, producing the largest data-set of relativistically intense laser–solid foil measurements to date. This tape drive provides robust targetry for the generation and study of high-repetition-rate ion beams using next-generation high-power laser systems, also enabling wider applications of laser-driven proton sources.
Maize is among major field crops which provides food, fodder and various byproducts to the industry. Development of better performing varieties is very important to enhance and strengthen the maize production system. In this study ethyl methanesulfonate (EMS) is used to induce genetic variation in maize. Mutant population was derived from two genotypes 100,003 and 100,004. EMS was applied under three different concentrations of 25, 50 and 75 mM. 25 mM was found as an ideal concentration resulting in maximum survival rate. Total 10 SSRs were used in this study, which amplified 28 alleles with average of 2.7 alleles. Analysis of molecular variance showed significant differences present among individuals. Average heterozygosity for mutants derived from 100,003 and 100,004 was 0.58 and 0.53, respectively. UPGMA analysis characterized the mutants into two main and many sub clusters. According to the principal component analysis, PC 1 and 2 contributed to 64.2% variability with eigenvalue greater than 1. Statistics showed maximum coefficients of variance in traits of leaf area, cobb height and plant height. Promising mutants were also identified and recommended for future breeding programme. In conclusion, EMS mutagenesis is an effective technique to develop novel mutants that can be exploited in future breeding programmes.
Among nursing home outbreaks of coronavirus disease 2019 (COVID-19) with ≥3 breakthrough infections when the predominant severe acute respiratory coronavirus virus 2 (SARS-CoV-2) variant circulating was the SARS-CoV-2 δ (delta) variant, fully vaccinated residents were 28% less likely to be infected than were unvaccinated residents. Once infected, they had approximately half the risk for all-cause hospitalization and all-cause death compared with unvaccinated infected residents.
Osteomyelitis of the frontal bone is a rare but devastating complication of frontal sinusitis. Treatment involves aggressive surgery to remove all sequestra in combination with long-term antibiotic therapy. However, systemic antibiotics may struggle to penetrate any remaining infection in devascularised areas, and the morbidity associated with surgical resection of some areas of the skull base is too high. In contrast, locally implanted antibiotics provide a reliable, high concentration of treatment to these areas while also minimising potential systemic side effects. The clinical application of tobramycin beads has primarily been used in orthopaedics as an adjunct to the treatment of tibial osteomyelitis or prosthetic joint infection.
To the best of the authors' knowledge, the two cases discussed here represent the first use of tobramycin antibiotic beads in frontal sinus osteomyelitis secondary to chronic rhinosinusitis.
These cases show promising use of tobramycin beads in recalcitrant frontal osteomyelitis.
Although pulmonary artery banding remains a useful palliation in bi-ventricular shunting lesions, single-stage repair holds several advantages. We investigate outcomes of the former approach in high-risk patients.
Retrospective cohort study including all pulmonary artery banding procedures over 9 years, excluding single ventricle physiology and left ventricular training.
Banding was performed in 125 patients at a median age of 41 days (2–294) and weight of 3.4 kg (1.8–7.32). Staged repair was undertaken for significant co-morbidity in 81 (64.8%) and anatomical complexity in 44 (35.2%). The median hospital stay was 14 days (interquartile range 8–33.5) and 14 patients (11.2%) required anatomical repair before discharge. Nine patients died during the initial admission (hospital mortality 7.2 %) and five following discharge (inter-stage mortality 4.8%). Of 105 banded patients who survived, 19 (18.1%) needed inter-stage re-admission and 18 (14.4%) required unplanned re-intervention. Full repair was performed in 93 (74.4%) at a median age of 13 months (3.1–49.9) and weight of 8.5 kg (3.08–16.8). Prior banding, 54% were below the 0.4th weight centile, but only 28% remained so at repair. Post-repair, 5/93 (5.4%) developed heart block requiring permanent pacemaker, and 11/93 (11.8%) required unplanned re-intervention. The post-repair mortality (including repairs during the initial admission) was 6/93 (6.5%), with overall mortality of the staged approach 13.6% (17/125).
In a cohort with a high incidence of co-morbidity, pulmonary artery banding is associated with a significant risk of re-intervention and mortality. Weight gain improves after banding, but heart block, re-intervention, and mortality remain frequent following repair.
Much has been learned about SARS-CoV-2. However, the mechanism of short or long-term neuropsychiatric symptoms remains unclear. several hypotheses, including lack of oxygen caused by lung damage, inflammation affecting brain cells, or Lack of blood flow caused by swelling of the small blood vessels in the brain, have been advanced to explain these symptoms.
Herein, we presented a case of cognitive impairment diagnosed after infection with COVID 19.
We discussed, through a clinical case, the possible mechanisms and risk factors of cognitive impairment following COVID 19 infection.
This case concerned a 28 –year-old patient. He had no personal or family psychiatric. In August 2021, he presented a SARS-CoV-2 infection without hypoxemia or respiratory failure. On day 10 the patient recovered. Two days after, he consulted our psychiatric department as he experienced impairment in memory. He had impairment in attention and executive function, and in particular verbal fluency. He said that his thinking was sluggish, fuzzy, and not sharp. He denied any alcohol or drug abuse. He was euthymic and he had no depressive symptoms. Arterial blood gas, laboratory, and clinical findings were normal. A brain CT scan with contrast was performed and did not show any abnormality.
This case highlighted the possible cognitive consequences of COVID-19 during the recovery phase. Further work is required to identify risk factors of psychiatric symptoms following COVID-19 infection and their management.
Trichinosis is a serious zoonotic disease that causes human morbidity and mortality. New effective natural remedies with minimal side effects that are well tolerated are needed to treat both enteral and parenteral trichinosis. This study evaluated the efficacy of selenium (Se), Se nanoparticles (SeNPs) and Egyptian propolis compared with albendazole as antiparasitic, anti-inflammatory and anti-angiogenic agents for treating murine trichinosis. We used parasitological, histopathological and immunohistochemical assays, as well as scanning electron microscopy, to examine adult worms. Overall, 80 Swiss albino male mice were divided into eight groups, with ten mice in each group, as follows: negative control, positive control, albendazole, propolis, Se, combination of propolis and Se, SeNPs and combination of SeNPs and propolis. Mice were slaughtered seven and 35 days after infection to examine the intestinal and muscular phases, respectively. This study demonstrated the efficacy of the combination of SeNPs and propolis. As revealed by electron microscopy, this combination caused damage to the adult worm cuticle. Additionally, compared with albendazole, it resulted in a significant reduction in adult worm and total larval counts; moreover, it caused a decrease in the number of larvae deposited in muscles, with a highly significant decrease in the inflammatory cell infiltrate around the larvae and a considerable decrease in the expression of the angiogenic marker vascular endothelial growth factor in muscles. In conclusion, the combination of SeNPs and propolis had antiparasitic, anti-inflammatory and anti-angiogenic effects on trichinosis. Consequently, this combination could be used as a natural alternative therapy to albendazole for treating trichinosis.
Background: The Canadian Medical Student Interest Group in Neurosurgery (CaMSIGN) is the first neurosurgery platform of its kind in Canada. Methods: In this retrospective study, data from CaMSIGN’s online platforms have been collated from February 2021 to the present and analyzed to show trends in user engagement. Results: CaMSIGN events generated 1,575 views on YouTube (384 from Canada). The total watch time was 170.3 hours, of which 43.9 hours were Canadian (28.5%). The total views normalized by the total number of students interested in neurosurgery was 17.12 hours. The normalized Canadian view was 4.17. 717 people follow the CaMSIGN Facebook account (normalized= 7.79). 152 people follow our Instagram (normalized= 1.65). 338 people follow our Twitter (normalized= 3.67). This number is comparable to that of estimated practicing neurosurgeons in Canada (333). A total of 32,974 people visited the Twitter page, with a monthly average of 2747.8. Lastly, the campaign website has had 5,811 visitors since its launch in June 2021 with a monthly average of 695.57 visitors. The number of website visitors has increased at a rate of 3.1327 visitors/month. Conclusions: Through this initiative, our aim has been to model a pan-Canadian approach to neurosurgery.
Background: While mechanical thrombectomy (MT) has become broadly used, many nuances around its performance are still contentious. In particular, the optimal sedation strategy for MT is not clear in the literature. Methods: This study was a single-center retrospective cohort study of a prospectively collected database. Age, gender, pre-treatment NIH stroke score (NIHSS), Alberta stroke program early score CT (ASPECTS), quality of collateralization, whether the patient underwent thrombectomy, tandem carotid occlusion, and thrombolysis in cerebral infarction (TICI) score were recorded in the database. Results: We identified 228 patients having anterior circulation mechanical thrombectomy (MT). 91 were right-sided, 108 were left-sided. Collaterals were graded as good in 135 (71.4), moderate in 44 (23.2%), and poor in 10 (5.3%). The average pre-MT ASPECTS was 8.1 (range). We found significant differences between all patients, patients with good outcome (mRS 0-2) and death in age, baseline NIHSS, collateralization, and TICI revascularization score. Multivariate analysis was performed with showed significant associations of sidedness, collateralization, TICI score and hemorrhage with neurological outcome. Right-sided stroke, better collaterals, higher TICI score and absence of hemorrhage were associated with better outcomes. Conclusions: We found comparable outcomes to those reported in the literature with use of general anesthetic. We identify several factors that influence outcomes.
Background: Despite a higher prevalence of traumatic spinal cord injury (TSCI) amongst Canadian Indigenous peoples, there is a paucity of studies focused on Indigenous TSCI. We present the first Canada-wide study comparing TSCI amongst Canadian Indigenous and non-Indigenous peoples. Methods: This study is a retrospective analysis of prospectively-collected TSCI data from the Rick Hansen Spinal Cord Injury Registry (RHSCIR) from 2004-2019. We divided participants into Indigenous and non-Indigenous cohorts and compared them with respect to demographics, injury mechanism, level, severity, and outcomes. Results: Compared with non-Indigenous patients, Indigenous patients were younger, more female, less likely to have higher education, and less likely to be employed. The mechanism of injury was more likely due to assault or transportation-related trauma in the Indigenous group. The length of stay for Indigenous patients was longer. Indigenous patients were more likely to be discharged to a rural setting, less likely to be discharged home, and more likely to be unemployed following injury. Conclusions: Our results suggest that more resources need to be dedicated for transitioning Indigenous patients sustaining a TSCI to community living and for supporting these patients in their home communities. A focus on resources and infrastructure for Indigenous patients by engagement with Indigenous communities is needed.
In late 2019, a novel coronavirus was detected in Wuhan, China, that caused a pandemic by September 2021, resulting in 224,180,411 cases and more than 4,600,000 deaths worldwide. In response to the pandemic, the Autonomous Kurdistan Regional Government of Iraq (KRG) imposed strict infection control measures at its borders for all travelers from neighboring countries, wherein each traveler was subjected to a mandatory reverse transcription polymerase chain reaction (RT-PCR) test on arrival to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infected travelers. The aim of this study is to determine the rate of infection with SARS-CoV-2 among the travelers entering Kurdistan region through Ibrahim Al-Khalil crossing point with Turkey as a predictor for the upcoming infection waves.
The data of RT-PCR tests to detect SARS-CoV-2 in all travelers arriving at the Ibrahim Al-Khalil Border Crossing between Iraq and the Republic of Turkey were reviewed from August 21, 2020 to August 21, 2021.
It was found that there were 9873 cases of SARS-CoV-2 infections among 1,082,074 travelers during the study period.
This study shows the importance of mass testing of travelers at border crossings to control the spread of SARS-CoV-2 infection.
The application of biological materials in everyday design is gaining traction and designers are encouraged to employ biological systems through biodesign and biophilia. However, there is a deficiency in the understanding of potential consumers’ perceptions. This paper compares the perception of non-designers as well as designers towards design-embedded bio-materials. Data was collected from 234 respondents using an online survey. The findings were gathered by evaluating perception in terms of desirability, practicality, aesthetically, and familiarity with living and non-living biomaterials.
In addition to risking their physical well-being, frontline physicians are enduring significant emotional burden both at work and home during the coronavirus disease 2019 (COVID-19) pandemic. This study aims to investigate the levels of anxiety and depressive symptoms and to identify associated factors among Bangladeshi physicians during the COVID-19 outbreak.
Methods and design
A cross-sectional study using an online survey following a convenience sampling technique was conducted between April 21 and May 10, 2020. Outcomes assessed included demographic questions, COVID-19 related questions, and the Hospital Anxiety and Depression Scale (HADS).
The survey was completed by 412 Bangladeshi physicians. The findings revealed that, in terms of standardized HADS cut-off points, the prevalence of anxiety and depressive symptoms among physicians was 67.72% and 48.5% respectively. Risk factors for higher rates of anxiety or depressive symptoms were: being female, physicians who had experienced COVID-19 like symptoms during the pandemic, those who had not received incentives, those who used self-funded personal protective equipment (PPE), not received adequate training, lacking perceived self-efficacy to manage COVID-19 positive patients, greater perceived stress of being infected, fear of getting assaulted/humiliated, being more connected with social media, having lower income levels to support the family, feeling more agitated, less than 2 h of leisure activity per day and short sleep duration. All these factors were found to be positively associated with anxiety and depression in unadjusted and adjusted statistical models.
This study identifies a real concern about the prevalence of anxiety and depressive symptoms among Bangladeshi physicians and identifies several associated factors during the COVID-19 pandemic. Given the vulnerability of the physicians in this extraordinary period whilst they are putting their own lives at risk to help people infected by COVID-19, health authorities should address the psychological needs of medical staff and formulate effective strategies to support vital frontline health workers.
Long haulers have been recently reported after contracting coronavirus disease (COVID-19). In the present study, we aimed to screen for the neuropsychiatric signs detected <1 to >6 months after infection by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and to determine whether vaccination has an effect on them.
An online survey was conducted among participants who had been diagnosed with laboratory-confirmed SARS-CoV-2 infection. The clinical signs and durations of neuropsychiatric complaints and their correlations to sex, age, severity of COVID-19 signs, and vaccination status were screened.
A total of 2218 individuals, including 1358 females and 860 males, with an age range of 12–70 years, submitted their responses. The respondents experienced cognitive dysfunction, mood alteration, depression, tinnitus, sleep disorders, and loss of taste and smell, with prevalence rates ranging from 18.9% (tinnitus) to 63.9% (loss of taste and smell). Of the respondents, 2.2–7.7% confirmed the persistence of symptoms for >6 months. Tinnitus was the least common complaint, and only 2.2% of the study participants had tinnitus for >6 months. Meanwhile, mood alteration persisted for >6 months in 7.6% of the study participants. More respondents who received two doses of BNT162b2 vaccine showed persistent symptoms than those in the other groups. Disease severity and female sex were identified as potential determinants of the development and persistency of such symptoms.
Post-COVID neuropsychiatric symptoms were present in considerable percentages of the study participants with SARS-CoV-2 infection, persisting for >6 months in up to 7.6% of the participants.