Abstract
Within the continuum of π‐extended quinoidal electronic structures exist molecules that by design can support open‐shell diradical structures. The prevailing molecular design criteria for ...such structures involve proaromatic nature that evolves aromaticity in open‐shell diradical resonance structures. A new diradical species built upon a quinoidal methano10annulene unit is synthesized and spectroscopically evaluated. The requisite intersystem crossing in the open‐shell structure is accompanied by structural reorganization from a contorted Möbius aromatic‐like shape in S
0
to a more planar shape in the Hückel aromatic‐like T
1
. This stability was attributed to Baird’s Rule which dictates the aromaticity of 4
n
π‐electron triplet excited states.
There is a great interest in peryleneimide (PI)-containing compounds given their unique combination of good electron accepting ability, high abosorption in the visible region, and outstanding ...chemical, thermal, and photochemical stabilities. Thus, herein we report the synthesis of perylene imide derivatives endowed with a 1,2-diketone functionality (PIDs) as efficient intermediates to easily access peryleneimide (PI)-containing organic semiconductors with enhanced absorption cross-section for the design of tunable semiconductor organic materials. Three processable organic molecular semiconductors containing thiophene and terthiophene moieties, PITa, PITb, and PITT, have been prepared from the novel PIDs. The tendency of these semiconductors for molecular aggregation have been investigated by NMR spectroscopy and supported by quantum chemical calculations. 2D NMR experiments and theoretical calculations point to an antiparallel π-stacking interaction as the most stable conformation in the aggregates. Investigation of the optical and electrochemical properties of the materials is also reported and analyzed in combination with DFT calculations. Although the derivatives presented here show modest electron mobilities of ∼10–4 cm2V–1s–1, these preliminary studies of their performance in organic field effect transistors (OFETs) indicate the potential of these new building blocks as n-type semiconductors.
Spontaneous rupture of hepatocellular carcinoma (HCC) is a potentially life-threatening complication. Diagnosis may be difficult, particularly in the absence of known liver cirrhosis or tumor. A ...20-year-old male patient presented with progressive abdominal pain and shock. His past medical history was uneventful. Anemia, acute renal failure, and abnormal liver function test were demonstrated. Mild hepatomegaly, perihepatic and flank fluid, and multiple hypodense liver lesions suggestive of intrahepatic metastases or multifocal HCC were revealed by computed tomography. Two actively bleeding liver tumors and multiple tumors in a noncirrhotic liver were found. Hemostatic suture and perihepatic packing were performed. The patient remained in critical condition, with a fatal outcome 48 h later. Histopathologic analysis reported HCC and absence of cirrhotic changes. HCC spontaneous rupture incidence is reported between 2.3 and 26%. Median age is 65 years. No liver cirrhosis is found in one-third of patients, with a median age of 51 years. Sudden onset of abdominal pain and shock is observed in the majority of cases. An accurate preoperative diagnosis improves to 75% with ultrasound and computed tomography. Besides hemodynamic stabilization, there is no general agreement on the best treatment option. Transarterial embolization, surgical perihepatic packing, suture plication, and hepatic artery ligation are useful methods of hemostasis in unstable patients. Mortality has been reported from 16.5 to 100%. The histopathologic finding of HCC in a noncirrhotic liver represents a less frequent presentation. A case of spontaneous rupture of HCC carcinoma and a noncirrhotic liver in a young patient is herein reported.
To predict successful prosthetic ambulation for patients immediately transferred to an inpatient rehabilitation facility after amputation surgery.
Seventy-five individuals with lower-limb amputation ...were studied at a tertiary acute care and rehabilitation facility. Successful prosthetic ambulation, defined as the ability to ambulate with a prosthesis at least 45 m, was measured in addition to other key demographic and medical factors.
Sixty-eight percent were successful prosthetic ambulators at rehabilitation discharge. The absence of residual-limb contracture and a longer length of stay during rehabilitation showed a significant relationship to successful prosthetic ambulation with regression analysis. Younger age was modestly correlated to outcome. There were no significant differences when comparing success of the early rehabilitation program with surgical level or etiology of amputation. For successful prosthetic users, mean wear time at rehabilitation discharge was 5.7 hours with a mean distance walked of 67 m. Of those who failed this approach, 70% were related to a failure of wound healing.
In this cohort, 68% of patients who were selected for a trial of early prosthetic rehabilitation ambulated using a prosthesis at rehabilitation discharge. This approach appears to be more effective for younger patients without contractures who are medically stable to participate in the rehabilitation process.
Celotno besedilo
Dostopno za:
DOBA, FSPLJ, IZUM, KILJ, NUK, OILJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK, VSZLJ
It is essential that orthopaedic resident physicians be highly proficient in all aspects, considering the balance between supply, demand, need and context. Fundamental to identify the capacity and ...quality installed for their training in Mexico.
Observational Study, transverse, non-probabilistic sampling-conglomerates, in two phases. The instrument has 8 domains, 57 variables and 4,867 items. 60 graduate professors of 20 states, 50 hospital sites, 22 university programs.
1,038 years of experience (collective intelligence), 17 years of experience/teacher (01 to 50 years). Identified: acute pathology 30 (2 to 90%), chronic pathology 30 (5 to 96%), patients 15 years, 10 (3 to 30%), patients between 15 and 65 years, 47 (2 to 78%), patients 65 years, 20 (2 to 60%), number of beds/seat 20 (2 to 510), number of clinics 3 (1 to 48), number of surgical procedures/headquarters per year at the national level, was 960 (50 to 24,650). The national average per resident doctor is 362 surgeries/year with 1,450 surgical times/year.
The needs and resources for the training of physicians specializing in orthopedics/traumatology are highly heterogeneous, so it should be adapted to the epidemiological needs of the region of influence, in an area of epidemiological transition. 62.2% expressed not having or have bad academic and scientific infrastructure at its headquarters, more than 50% without rotation overseas and 90% without regular scientific production.
Rational design of a malaria vaccine may result from the structure–immunogenicity relationship of analogues of peptide 1585, a protein sequence located at the N‐terminal end of the P. falciparum ...42‐kDa merozoite surface protein‐1. Altering a few amino acids in peptide 1585 (left) induces immunogenicity and protectivity, and changes the 3D structure, as shown for one of the analogues synthesized (right).
Antigen structure modulation represents an approach towards designing subunit malaria vaccines. A specific epitope's α carbon stereochemistry, as well as its backbone topochemistry, was assessed for ...obtaining novel malarial immunogens. A variety of MSP-1
38–61
Plasmodium falciparum epitope pseudopeptides derived were synthesised, based on solid-phase pseudopeptide chemistry strategies; these included all-
l, all-
d, partially-
d substituted, all-Ψ-NH-CO-
Retro, all-Ψ-NH-CO-
Retro-inverso, and Ψ-CH
2NH reduced amide surrogates. We demonstrate that specific recombinant MSP-1
34–469 fragment binding to red blood cells (RBCs) is specifically inhibited by non-modified MSP-1
42–61, as well as by its V
52-L
53, M
51-V
52 reduced amide surrogates and partial-
d substitutions in K
48 and E
49. In vivo tests revealed that reduced amide pseudopeptide-immunised
Aotus monkeys induced neutralising antibodies specifically recognising the MSP-1 N-terminus region. These findings support the role of molecular conformation in malaria vaccine development.
Human papillomavirus type 16 (HPV-16) represents the major cervical carcinoma associated virus among women, especially in Colombia. It has thus become important to develop reliable inexpensive tests ...for detecting the presence of this virus. It has been shown that HPV16-E7 oncoprotein structural features have three α-helical structures and a loop-like structure. The hydrazone link approach was used to mimic helix secondary substructures. Sera from women with invasive cervical carcinoma were tested against conformationally restricted peptides and their respective linear peptides to identify conformational epitopes. One peptide that was conformationally restricted to an α-helix showed very strong positive reaction with sera from women having invasive cervical carcinoma; there was no reaction with sera from patients with other carcinomas, children, or healthy women. NMR studies confirmed this peptide's α-helical structure. The observation that constrained protein substructure peptidomimetics can identify new conformationally sensitive antibodies in cervical carcinoma patients' sera is very important, since these antibodies are almost all generated by native proteins, providing a new selection of antibodies for diagnostic and vaccine studies.
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