When to take the primary certification examination: sooner or later?

Most Pathology residents take the Anatomic Pathology and/or Clinical Pathology primary pathology certification examination(s) near the end of their final year of training (i.e., Spring), whereas some postpone the examination(s) to the Fall administration of that year or even later. We compared the Spring and Fall administration pass rates of initial primary certification candidates for those who graduated in the same year they took the examination. We also compared the pass rates of same-year graduates with individuals who postponed the examination for a year or more. We also surveyed the candidates regarding the reasons they chose the Spring or Fall administration. Candidates who chose the earlier (i.e., Spring) administration were more likely to pass compared with those who took the later Fall administration (p = 0.0026 for Anatomic Pathology; p = 0.0004 for Clinical Pathology). Delaying the certifying exams beyond the calendar year of residency graduation was associated with a higher failure rate (p < 0.0001 for both Anatomic and Clinical Pathology). The survey results suggest that residents often take their certification examinations earlier to not interfere with fellowship training, because it coincides with the completion of residency training, or it is expected by their program. Pathology residents are more likely to pass the primary certification examinations when they are taken closer to the end of training, rather than postponing it to a later administration. Pathology residency program directors should encourage residents, who are deemed ready, to take their certification examinations at the earliest possible administration.

Design of the first fusion experiment to achieve target energy gain G>1

In this work we present the design of the first controlled fusion laboratory experiment to reach target gain G>1 N221204 (5 December 2022) [Phys. Rev. Lett. 132, 065102 (2024)10.1103/PhysRevLett.132.065102], performed at the National Ignition Facility, where the fusion energy produced (3.15 MJ) exceeded the amount of laser energy required to drive the target (2.05 MJ). Following the demonstration of ignition according to the Lawson criterion N210808, experiments were impacted by nonideal experimental fielding conditions, such as increased (known) target defects that seeded hydrodynamic instabilities or unintentional low-mode asymmetries from nonuniformities in the target or laser delivery, which led to reduced fusion yields less than 1 MJ. This Letter details design changes, including using an extended higher-energy laser pulse to drive a thicker high-density carbon (also known as diamond) capsule, that led to increased fusion energy output compared to N210808 as well as improved robustness for achieving high fusion energies (greater than 1 MJ) in the presence of significant low-mode asymmetries. For this design, the burnup fraction of the deuterium and tritium (DT) fuel was increased (approximately 4% fuel burnup and a target gain of approximately 1.5 compared to approximately 2% fuel burnup and target gain approximately 0.7 for N210808) as a result of increased total (DT plus capsule) areal density at maximum compression compared to N210808. Radiation-hydrodynamic simulations of this design predicted achieving target gain greater than 1 and also the magnitude of increase in fusion energy produced compared to N210808. The plasma conditions and hotspot power balance (fusion power produced vs input power and power losses) using these simulations are presented. Since the drafting of this manuscript, the results of this paper have been replicated and exceeded (N230729) in this design, together with a higher-quality diamond capsule, setting a new record of approximately 3.88MJ of fusion energy and fusion energy target gain of approximately 1.9.

Mechanics of particulate composites with glassy polymer binders in compression

Whether used as structural components in design or matrix materials for composites, the mechanical properties of polymers are increasingly important. The compressive response of extruded polymethyl methacrylate (PMMA) rod with aligned polymer chains and Al-Ni-PMMA particulate composites are investigated across a range of strain rates and temperatures. The particulate composites were prepared using an injection-moulding technique resulting in highly anisotropic microstructures. The mechanics of these materials are discussed in the light of theories of deformation for glassy polymers. The experimental data from this study are compared with PMMA results from the literature as well as epoxy-based composites with identical particulates. The PMMA exhibited the expected strain rate and temperature dependence and brittle failure was observed at the highest strain rates and lowest temperatures. The Al-Ni-PMMA composites were found to have similar stress-strain response to the PMMA with reduced strain softening after yield. Increasing volume fraction of particulates in the composite resulted in decreased strength.

DeltaF508 CFTR processing correction and activity in polarized airway and non-airway cell monolayers

We examined the activity of DeltaF508 cystic fibrosis transmembrane conductance regulator (CFTR) stably expressed in polarized cystic fibrosis bronchial epithelial cells (CFBE41o(-)) human airway cells and Fisher Rat Thyroid (FRT) cells following treatment with low temperature and a panel of small molecule correctors of DeltaF508 CFTR misprocessing. Corr-4a increased DeltaF508 CFTR-dependent Cl(-) conductance in both cell types, whereas treatment with VRT-325 or VRT-640 increased activity only in FRT cells. Total currents stimulated by forskolin and genistein demonstrated similar dose/response effects to Corr-4a treatment in each cell type. When examining the relative contribution of forskolin and genistein to total stimulated current, CFBE41o(-) cells had smaller forskolin-stimulated I(sc) following either low temperature or corr-4a treatment (10-30% of the total I(sc) produced by the combination of both CFTR agonists). In contrast, forskolin consistently contributed greater than 40% of total I(sc) in DeltaF508 CFTR-expressing FRT cells corrected with low temperature, and corr-4a treatment preferentially enhanced forskolin dependent currents only in FRT cells (60% of total I(sc)). DeltaF508 CFTR cDNA transcript levels, DeltaF508 CFTR C band levels, or cAMP signaling did not account for the reduced forskolin response in CFBE41o(-) cells. Treatment with non-specific inhibitors of phosphodiesterases (papaverine) or phosphatases (endothall) did not restore DeltaF508 CFTR activation by forskolin in CFBE41o(-) cells, indicating that the Cl(-) transport defect in airway cells is distal to cAMP or its metabolism. The results identify important differences in DeltaF508 CFTR activation in polarizing epithelial models of CF, and have important implications regarding detection of rescued of DeltaF508 CFTR in vivo.

Merkel cell carcinoma: an overview and case report

Merkel cell carcinoma is an extremely rare neoplasm with a high rate of recurrence and metastasis. The lesions predominantly arise on sun-exposed areas of skin in whites between the sixth and seventh decades of life. Within the head and neck region, the cheeks and eyelids are the most common sites. This article outlines the etiology, pathogenesis, and treatment of this rare but highly aggressive tumor.

Telehealth and communication technologies in health: summary and action plan

INTRODUCTION

Rapid innovations and improvements in communication technologies have opened many new channels for health education and delivery, as well as disaster management. Theme 2 examined the role and applicability of these technologies to Disaster Medicine and Management and the various issues involved in their use.

METHODS

Details of the methods used are provided in the introductory paper. The chairs moderated all presentations and produced a summary that was presented to an assembly of all of the delegates. The chairs then presided over a workshop that resulted in the generation of a set Action Plans that then were reported to the collective group of all delegates.

RESULTS

Main points developed during the presentations and discussion included harnessing convergence, seeking interoperability, building partnerships and making it appropriate. This group identified four Principles of Action underlying its plan: (1) investigate possibilities, (2) identify stakeholders, (3) invite participation, and (4) involve discussants in activities.

DISCUSSION

Action plans were categorized into three areas that included "thinking globally, acting regionally", forming a telehealth advisory group, and increasing corporate partnerships.

CONCLUSIONS

Technology is opening many opportunities that have applications in disaster management. To optimize benefits, goals and standards must be agreed upon and implemented.

Use of 2-acetamidophenanthrene and 2-acetamidofluorene in investigations of mechanisms of hepatocarcinogenesis

Comparison studies have been undertaken on the hepatocarcinogen 2-acetamidofluorene (AAF) and its nonhepatocarcinogenic analog 2-acetamidophenanthrene (AAP). Previous studies have shown that amount of compound acutely and persistently bound to rat liver DNA is comparable for the two compounds following single injections into adult Fischer rats, but that AAP fails to initiate tumors in weanling Sprague-Dawley rats. In this work we show that the amount of bound adduct from AAF and AAP is also comparable after three weeks of feeding compound to weanling Sprague-Dawley male rats. Three of the adducts found in RNA of AAP-treated rats cochromatographed on Sephadex LH-20 with two adenosine adducts and one guanosine adduct prepared by reaction of the nucleosides with N-acetoxy-N-trifluoroacetyl-2-aminophenanthrene at neutrality. Because of the lack of initiating ability of AAP in liver, we have also investigated early biochemical alterations in liver after various regimens. Feeding of either AAF or AAP to male weanling rats, followed by three weeks of DDT feeding produced no alteration in either histochemically detected gamma-glutamyltranspeptidase or in ganglioside complement in total liver homogenate. Partial hepatectomy after feeding of either AAF or AAP resulted in the appearance of new fucoganglioside and alteration in the distribution of the major gangliosides. DDT feeding after partial hepatectomy resulted in foci of elevated gamma-glutamyltranspeptidase in AAF-fed rats but not in AAP-fed rats. These results support a previous proposal that AAP may initiate tumorigenesis in rat liver, but that the promoting regimens now in use lack the ability to cause further progression of the initiated cells. The data also suggests that ganglioside synthesis may be a more sensitive marker for early stages in carcinogenesis than are the various histochemical stains now in use.

The influence of molecular size and partition coefficients on the predictability of tumor initiation in mouse skin from mutagenicity in Salmonella typhimurium

Initiation of tumors in mouse skin is well correlated with mutagenesis in hamster V79 cells (correlation coefficient r = 0.88), but is poorly correlated with bacterial mutagenicity in the Ames assay (r = 0.58). Efforts to understand the difference in the degrees of correlation led to the observation that if the bacterial mutagenicity data are combined with a molecular size or partition factor, the correlation of initiating activity with this combined parameter approaches that found with the hamster cell mutagenesis. The improvement in correlation (r = 0.84) leads to the suggestion that when a broad size range of compounds is considered a most important factor in accounting for the poor correlation initially observed may be a difference between mammalian and bacterial cells in permeability or target access.