An electronic (e‐) skin is expected to experience significant wear and tear over time. Therefore, self‐healing stretchable materials that are simultaneously soft and with high fracture energy, that ...is high tolerance of damage or small cracks without propagating, are essential requirements for the realization of robust e‐skin. However, previously reported elastomers and especially self‐healing polymers are mostly viscoelastic and lack high mechanical toughness. Here, a new class of polymeric material crosslinked through rationally designed multistrength hydrogen bonding interactions is reported. The resultant supramolecular network in polymer film realizes exceptional mechanical properties such as notch‐insensitive high stretchability (1200%), high toughness of 12 000 J m−2, and autonomous self‐healing even in artificial sweat. The tough self‐healing materials enable the wafer‐scale fabrication of robust and stretchable self‐healing e‐skin devices, which will provide new directions for future soft robotics and skin prosthetics.
An extremely tough and water‐insensitive self‐healing elastomer crosslinked through multistrength hydrogen bonding interactions is described. The resultant crosslinking network in polymer film realizes exceptional mechanical properties such as notch‐insensitive high stretchability (1200%), a high toughness of 12 000 J m−2, and autonomous self‐healing even in artificial sweat. The tough self‐healing materials enable the wafer‐scale fabrication of robust and stretchable self‐healing e‐skin devices.
The purpose of this American Gastroenterological Association Institute Clinical Practice Update is to describe the indications for screening for pancreas cancer in high-risk individuals.
The evidence ...reviewed in this work is based on reports of pancreas cancer screening studies in high-risk individuals and expert opinion.
Pancreas cancer screening should be considered in patients determined to be at high risk, including first-degree relatives of patients with pancreas cancer with at least 2 affected genetically related relatives.
Pancreas cancer screening should be considered in patients with genetic syndromes associated with an increased risk of pancreas cancer, including all patients with Peutz–Jeghers syndrome, hereditary pancreatitis, patients with CDKN2A gene mutation, and patients with 1 or more first-degree relatives with pancreas cancer with Lynch syndrome, and mutations in BRCA1, BRCA2, PALB2, and ATM genes.
Genetic testing and counseling should be considered for familial pancreas cancer relatives who are eligible for surveillance. A positive germline mutation is associated with an increased risk of neoplastic progression and may also lead to screening for other relevant associated cancers.
Participation in a registry or referral to a pancreas Center of Excellence should be pursued when possible for high-risk patients undergoing pancreas cancer screening.
Clinicians should not screen average-risk individuals for pancreas cancer.
Pancreas cancer screening in high-risk individuals should begin at age 50 years, or 10 years younger than the initial age of familial onset. Screening should be initiated at age 40 years in CKDN2A and PRSS1 mutation carriers with hereditary pancreatitis and at age 35 years in the setting of Peutz–Jeghers syndrome.
Magnetic resonance imaging and endoscopic ultrasonography (EUS) should be used in combination as the preferred screening modalities in individuals undergoing pancreas cancer screening.
The target detectable pancreatic neoplasms are resectable stage I pancreatic ductal adenocarcinoma and high-risk precursor neoplasms, such as intraductal papillary mucinous neoplasms with high-grade dysplasia and some enlarged pancreatic intraepithelial neoplasias.
Screening intervals of 12 months should be considered when there are no concerning pancreas lesions, with shortened intervals and/or the performance of EUS in 6–12 months directed towards lesions determined to be low risk (by a multidisciplinary team). EUS evaluation should be performed within 3–6 months for indeterminate lesions and within 3 months for high-risk lesions, if surgical resection is not planned. New-onset diabetes in a high-risk individual should lead to additional diagnostic studies or change in surveillance interval.
Decisions regarding therapy directed towards abnormal findings detected during screening should be made by a dedicated multidisciplinary team together with the high-risk individual and their family.
Surgical resection should be performed at high-volume centers.
Clinicians should consider discontinuing pancreas cancer screening in high-risk individuals when they are more likely to die of non-pancreas cancer–related causes due to comorbidity and/or are not candidates for pancreas resection.
The limitations and potential risks of pancreas cancer screening should be discussed with patients before initiating a screening program.
Nonconjugated segments in polymer semiconductors have been utilized to improve the processability of semiconducting polymers. Recently, several reports have described the improvement of ...stretchability of polymer semiconductors by incorporating nonconjugated spacers. However, the effect of relative flexibility of such conjugation breakers on mechanical and electrical properties has not yet been studied systematically. Here, conjugation breakers with different chain length and rigidity are incorporated into the backbone of diketopyrrolopyrrole‐based semiconductors. Interestingly, it is observed that the longer and more flexible conjugation breakers result in greater ductility and lower elastic modulus without significantly affecting mobility. The enhancement of stretchability is attributed to the reduced modulus and the decrease in crystallinity, as confirmed by X‐ray diffraction. With this newly established molecular design, transistors are prepared with a semiconducting polymer containing dodecyl segments as conjugation breakers. It is observed that this polymer retains a mobility of >0.36 cm2 V−1 s−1 at 100% strain, and after 100 cycles at 50% strain. Finally, its high stability against strain is also observed with a fully stretchable transistor fabricated. Taken together, the above results indicate that molecular engineering of conjugated polymers, i.e., by incorporating suitable conjugation breakers, can effectively tune mechanical properties without significantly compromising their electrical properties.
The effect of nonconjugated spacers on mechanical properties of polymer semiconductors is discussed. Longer and more flexible conjugation breakers lead to greater ductility and lower modulus without significant compromise in mobility. Specifically, a semiconducting polymer containing dodecyl segments maintains a moderate mobility (≈0.1 cm2 V−1 s−1) under 100% strain, and after 100 cycles at 50% strain.
Gastric cancer is a heterogeneous cancer, making treatment responses difficult to predict. Here we show that we identify two distinct molecular subtypes, mesenchymal phenotype (MP) and epithelial ...phenotype (EP), by analyzing genomic and proteomic data. Molecularly, MP subtype tumors show high genomic integrity characterized by low mutation rates and microsatellite stability, whereas EP subtype tumors show low genomic integrity. Clinically, the MP subtype is associated with markedly poor survival and resistance to standard chemotherapy, whereas the EP subtype is associated with better survival rates and sensitivity to chemotherapy. Integrative analysis shows that signaling pathways driving epithelial-to-mesenchymal transition and insulin-like growth factor 1 (IGF1)/IGF1 receptor (IGF1R) pathway are highly activated in MP subtype tumors. Importantly, MP subtype cancer cells are more sensitive to inhibition of IGF1/IGF1R pathway than EP subtype. Detailed characterization of these two subtypes could identify novel therapeutic targets and useful biomarkers for prognosis and therapy response.
This large, phase 2 study confirms a response rate of more than 50% and a median survival of 16 months among patients with metastatic melanoma treated with vemurafenib. Some patients did not have a ...response until after 6 or more months of therapy.
Patients with metastatic melanoma have a median survival of 6 to 10 months.
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Few patients have a response to systemic therapies.
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Ipilimumab, a monoclonal antibody that blocks cytotoxic T-lymphocyte–associated antigen 4 (CTLA4) on lymphocytes, has recently been associated with superior overall survival, with median overall survival of 10.1 months among previously treated patients and 11.2 months among previously untreated patients.
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However, the majority of patients do not have a response to anti-CTLA4 antibody therapy and still need effective therapeutic options.
In 2002, investigators at the Sanger Institute discovered that mutations in the gene encoding the serine–threonine protein . . .
Diverse signals generated from the sensing elements embedded in flexible electronic skins (e‐skins) are typically interfered by strain energy generated through processes such as touching, bending, ...stretching or twisting. Herein, we demonstrate a flexible bimodal sensor that can separate a target signal from the signal by mechanical strain through the integration of a multi‐stimuli responsive gate dielectric and semiconductor channel into the single field‐effect transistor (FET) platform.
Electronic skin devices capable of monitoring physiological signals and displaying feedback information through closed-loop communication between the user and electronics are being considered for ...next-generation wearables and the 'Internet of Things'. Such devices need to be ultrathin to achieve seamless and conformal contact with the human body, to accommodate strains from repeated movement and to be comfortable to wear. Recently, self-healing chemistry has driven important advances in deformable and reconfigurable electronics, particularly with self-healable electrodes as the key enabler. Unlike polymer substrates with self-healable dynamic nature, the disrupted conducting network is unable to recover its stretchability after damage. Here, we report the observation of self-reconstruction of conducting nanostructures when in contact with a dynamically crosslinked polymer network. This, combined with the self-bonding property of self-healing polymer, allowed subsequent heterogeneous multi-component device integration of interconnects, sensors and light-emitting devices into a single multi-functional system. This first autonomous self-healable and stretchable multi-component electronic skin paves the way for future robust electronics.
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