The role of printed electronics and related technologies in the development of smart connected products

The emergence of novel materials with flexible and stretchable characteristics, and the use of new processing technologies, have allowed for the development of new connected devices and applications. Using printed electronics, traditional electronic elements are being combined with flexible components and allowing for the development of new smart connected products. As a result, devices that are capable of sensing, actuating, and communicating remotely while being low-cost, lightweight, conformable, and easily customizable are already being developed. Combined with the expansion of the Internet of Things, artificial intelligence, and encryption algorithms, the overall attractiveness of these technologies has prompted new applications to appear in almost every sector. The exponential technological development is currently allowing for the ‘smartification’ of cities, manufacturing, healthcare, agriculture, logistics, among others. In this review article, the steps towards this transition are approached, starting from the conceptualization of smart connected products and their main markets. The manufacturing technologies are then presented, with focus on printing-based ones, compatible with organic materials. Finally, each one of the printable components is presented and some applications are discussed.This work has been supported by NORTE-06-3559- FSE-000018, integrated in the invitation NORTE59-2018-41, aiming the Hiring of Highly Qualified Human Resources, co-financed by the Regional Operational Programme of the North 2020, thematic area of Competitiveness and Employment, through the European Social Fund (ESF), and by the scope of projects with references UIDB/05256/2020 and UIDP/05256/2020, financed by FCT—Fundação para a Ciência e Tecnologia, Portugal

A review on materials and technologies for organic large-area electronics

New and innovative applications in the field of electronics are rapidly emerging. Such applications often require flexible or stretchable substrates, lightweight and transparent materials, and design freedom. This paper offers a complete overview concerning flexible electronics manufacturing, focusing on the materials and technologies that have been recently developed. This combination of materials and technologies aims to fuel a fast, economical, and environmentally sustainable transition from the conventional to the novel and highly customizable electronics. Organic conductors, semiconductors, and dielectrics have recently gathered lots of attention since they are compatible with printing technologies, and can be easily spread over large and flexible substrates. These printing technologies are usually simple and fast procedures, which rely on low-cost and recycle-friendly materials, intended for large-scale fabrication. Overall, even though organic large-area electronics manufacturing is still in its early stages of development, it is a field with tremendous potential that holds promise to revolutionize the way products are designed, developed, and processed from the factory premises to the consumers’ hands. Besides, this technology is highly versatile and can be applied to a large array of sectors such as automotive, medical, home design, industrial, agricultural, among others.This work was supported by NORTE-06-3559-FSE-000018, integrated in the invitation NORTE-59-2018-41, aiming the Hiring of Highly Qualified Human Resources, co-financed by the Regional Operational Programme of the North 2020, thematic area of Competitiveness and Employment, through the European Social Fund (ESF), and by the scope of projects with references UIDB/05256/2020 and UIDP/05256/2020, financed by FCT – Fundação para a Ciência e Tecnologia, Portugal. The authors also thank Prof. Luís A. Rocha for his support and guidance during the writing of this review work

Physico-chemical characteristics of immobilized polygalacturonase from Aspergillus niger (SA6)

Polygalacturonase (PG) was isolated from Aspergillus niger (A. niger) (SA6), partially purified, characterized and immobilized by entrapment using calcium alginate. The polygalacturonase showed two bands on sodium dodecyl sulfate polyacryamide gel electrophoresis (SDS-PAGE) suggesting an “endo and exo” polygalacturonase with apparent molecular weights of 35 and 40 KDa, respectively. The enzyme was purified 9 fold with a yield of 0.18% and specific activity of 246 μmole/min/mg. The apparent KM and Vmax of the immobilized polygalacturonase were11.1 mg/ml and 1.65 μmole/min/mg, respectively. The optimum pH and optimum temperature of the immobilized polygalacturonase were 4.5 and 40°C, respectively. Immobilized polygalacturonase exhibited more stability to changes in pH than the temperature. The activity of the immobilized polygalacturonase reduced to 34.56 and 14.81% of the initial activity in the second and third catalytic cycles, respectively. The half life of the enzyme and theactivity lost per minute on thermal storage were 10 min and 0.0213 μMole of D-galacturonic acid.Keywords: Polygalacturonase, Aspergillus niger, pectinases, enzyme

Notes on Trichosiphonaphis (Xenomyzus) cortices Aizenberg, 1935 and T. (X.) foliotus Shaposhnikov in Juchnevitch, 1968, nomem nudum (Homoptera: Aphididae)

Description of oviparous females and the first description of aptcrous males of Trichosiphe naphis (Xmomyrus) corZicis (Aizenberg. 1935) are given. T. (X) foliotus Shaposhnikov in Juchnevitch. 1968 is a nomcn nudum and synonym of Loniceraphis paradoxus Narzikulov, 1962

Unconventional Magnetization below 25 K in Nitrogen-doped Diamond provides hints for the existence of Superconductivity and Superparamagnetism

The magnetization of nitrogen-doped single crystalline diamond bulk samples shows unconventional field and temperature hysteresis loops at T ≲ 25 K. The results suggest the existence of superparamagnetic and superconducting regions in samples with nitrogen concentration <200 ppm. Both phases vanish at temperatures above 25 K where the samples show diamagnetic behavior similar to undoped diamond. The observation of superparamagnetism and superconductivity is attributed to the nitrogen doping and to the existence of defective regions. From particle-induced X-ray emission with ppm resolution we rule out that the main observations below 25 K are due to magnetic impurities. We investigated also the magnetic properties of ferromagnetic/high-temperature superconducting oxide bilayers. The magnetization results obtained from those bilayers show remarkable similarities to the ones in nitrogen-doped diamond

Characterization of microstructured multiwalled carbon nanotube/polydimethylsiloxane composites for piezoresistive sensing applications

Technological advancements in the field of flexible and printed electronics are creating a need for large-area sensors that can be embedded over different types of surfaces. Such sensors can be used to monitor physical signals over flexible, curved, or soft devices. Hence, it is herein proposed, a formulation to produce piezoresistive multiwalled carbon nanotube/polydimethylsiloxane (MWCNT/PDMS) composites with tunable electric properties for pressure sensing purposes. The composite is obtained through few manufacturing steps, avoiding the use of hazardous solvents. Different weight percentages of MWCNT dispersed in PDMS are evaluated and the results evidence that using 3.0 wt% of infill is sufficient to obtain highly sensitive sensors. To enhance the dispersion of the MWCNT and add microstructure to the composite, a system composed of a surfactant and foaming agent is used. Finally, pressure sensing units and arrays are printed and tested. The sensors present fast response, low hysteresis, repeatability, and a sensing range of 0–160 kPa. The composite is more sensitive to lower pressure and a maximum sensitivity of 8.0% kPa−1 is achieved for porous composites at pressure <10 kPa. Thanks to these characteristics, the sensors are successfully used in the development of a pressure sensing array and heartbeat sensor for proof of concept.This work has been supported by NORTE-06-3559-FSE-000018, integrated in the invitation NORTE-59-2018-41, aiming the Hiring of Highly Qualified Human Resources, co-financed by the Regional Operational Programme of the North 2020, thematic area of Competitiveness and Employment, through the European Social Fund (ESF), and by the scope of projects with references UIDB/05256/2020 and UIDP/05256/2020, financed by FCT—Fundação para a Ciência e Tecnologia, Portugal

Addition to the aphid fauna of Belorussia (Homoptera: Aphidoidea) with detailed description of sexuales of Semiaphis anthrisci (Kaltenbach, 1843)

For the fi rst time, Therioaphis luteola (Börner, 1949), Aphis chloris Koch, 1854, Aphis craccae Linnaeus, 1758, Aphis galiiscabri Schrank, 1801, Aphis newtoni Theobald, 1927, Aphis thalictri Koch, 1854, Aphis (Bursaphis) epilobiaria Theobald, 1927, Brachycaudus (Appelia) tragopoginis (Kaltenbach, 1843), Brachycaudus (Brachycaudina) aconiti (Mordvilko, 1928), Dysaphis hirsutissima (Börner, 1940), Acaudinum centaureae (Koch, 1854), Hydaphias molluginis Börner, 1939, Semiaphis anthrisci (Kaltenbach, 1843), Uroleucon (Lambersius) erigeronense (Thomas, 1878) and Uroleucon (Uromelan) campanulae (Kaltenbach, 1843) are recorded from Byelorussia. The detailed description of oviparous female and male of S. anthrisci are given

Surgical treatment of abdominal aortic aneurisms

Secția Chirurgie Vasculară IMSP SCR, Al XI-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” din Republica Moldova și cea de-a XXXIII-a Reuniune a Chirurgilor din Moldova „Iacomi-Răzeșu” 27-30 septembrie 2011În secția chirurgie vasculară a IMSP SCR, pe parcursul anilor 1988-2010 au fost operați 224 pacienți cu anevrisme ale aortei abdominale. SCa criteriu diagnostic pentru anevrism s-a considerat dilatarea aortei abdominale cu două diametre şi mai mult. Vârsta pacienților a fost cuprinsă între 15 şi 89 ani. Din totalul de pacienți 79,5%(178) au fost bărbați şi 20,5%(46) femei. La 18,75%(42) pacienți anevrismele au fost complicate prin ruptură completă sau incompletă, fiind operați în regim de urgență imediată. Etiologia a fost: ateroscleroza - 94,65% (212), aortoarteriita nespecifică - 3,57% (8), sindromul Marfan - 1,78% (4). Diagnosticul a fost stabilit clinic, ultrasonografic, prin Duplex vascular, angio-CT, aortografie, RMN. În 3 cazuri (1,34%) anevrismul implica şi arterele renale. Doi pacienți, neincluşi în studiu, au decedat preoperator prin hemoragie masivă cauzată de ruptura spontană a anevrismului în duoden şi cavitatea abdominală liberă. Toți pacienții au fost supuşi rezecției anevrismului aortal cu protezare aorto-distală (aortală, biiliacă, ilio-femurală, bifemurală), iar în 3 cazuri cu replantarea arterelor renale şi viscerale. Mortalitatea în anevrismele rupte a fost 57% (24), iar în cele complicate - 8% (18). Concluzii: pe parcursul ultimilor 5 ani a crescut ponderea pacienților cu anevrisme simptomatice sau deja complicate prin ruptură, astfel că toți pacienții cu factori de risc trecuți de 50 ani trebuie supuşi screening-ului prin USG sau Dopplerografie. Mortalitatea postoperatorie în anevrismele rupte s-a micşorat cu 13 %, iar în cele operate programat cu 7,55%. Implimentarea metodei endovasculare ar permite reducerea substanțială a acestui indice, mai ales în cazul anevrismelor complicate prin ruptură.During the period of 1988 - 2010, 224 patients underwent surgery for abdominal aortic aneurisms. The main diagnostic criteria was dilatation of the abdominal aorta by two diameters and more. All patients were aged between 15 and 89. Of all patients 79,5% (178) were males and 20,5% (46) were female. In 18,75% (42) cases, a complete or incomplete rupture of the aneurisms occurred. These patients underwent urgent surgery. Etiology: atherosclerosis – 94,65% (212), nonspecific aortoarteritis – 3,57% (8), Marfan syndrome – 1,78% (4). The diagnosis was made by clinical findings, vascular Duplex scanning, angio-CT and MRI. In 3(1,34%) cases the aneurism involved the renal arteries. There were two lethal outcomes, one caused by spontaneous rupture of the aneurism in the duodenum and the second caused by rupture into the peritoneal cavity. These cases were not included in the study. All patients underwent aneurism resection with aortal –distal (aortic, biiliac, ilio-femural, bifemural) allografting, while in three cases reimplantation of the renal arteries was necessary. The mortality in cases of ruptured aneurisms consisted 57% (24), and in cases of uncomplicated aneurisms – 8% (18).Conclusions: During the last 5 years we observed a raise in the rate of symptomatic aneurisms, including those complicated with rupture. Aortic ultrasonography or dopplerography should be used as screening methods in all patients, with risk factors, that are aged 50 and more. Postoperative mortality in cases of ruptured aneurisms has decreased by 13%, while in cases of planned aneurism surgery by 7,55%. Implementation of endovascular techniques would reduce substantially these indices

The use of extraanatomic by-passes in vascular surgery

Republica Moldova, IMSP SCR, Secția Chirurgie vasculară, Al XI-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” din Republica Moldova și cea de-a XXXIII-a Reuniune a Chirurgilor din Moldova „Iacomi-Răzeșu” 27-30 septembrie 2011Pînă în prezent nu sunt stabilite cu precizie indicațiile pentru intervenție, tehnicile de aplicare a by-passului extraanatomic şi criteriile de selectare a pacienților. Studiul de față are ca scop elucidarea acestor probleme folosind analiza rezultatelor a unui eşantion de 38 pacienți cu by-passuri extraanatomice operați în perioada anilor 1987- 2010. Indicații pentru efectuarea by-passului extraanatomic a fost ischemia critică a membrelor inferioare asociată cu patologia cardiovasculară şi pulmonară avansată la 21 de pacienți. Alt grup la care s-au aplicat by-passuri de ocolire a fost format din 6 pacienți cu procese supurative. La pacienții cu trautisme vasculare asociate cu distrugere importantă şi infectare a țesuturilor adiacente au fost aplicate 11 by-passuri extraanatomice. Rezultatele obținute depind în mare masură de patul vascular periferic. La pacienții cu ischemie critică pe fondalul aterosclerozei obliterante, cu patologie cardiovasculară şi pulmonară avansată sau cu procese supurative se presupunea o posibilă afectare cronică a patului periferic, astfel rezultatele fiind nu cele mai bune – aproximativ jumatate din by-passuri s-au trombozat în perioada postoperatorie precoce ori la un an. La pacienții cu traumatisme vasculare care prezentau un pat vascular periferic permiabil, toate by-passurile erau funcționale pe toată perioada de observație (de la 1 la 11 ani). Aşadar, şunturile extraanatomice prezintă o alternativă revascularizarilor clasice la anumite grupuri de pacienți şi sunt unica şansă de salvare a membrelor. Aceste proceduri sunt indicate pacienților cu procese supurative, pentru ocolirea zonei afectate. Un alt grup prezintă pacienții cu patologie cardiovasculară şi pulmonară avansată, astfel by-passurile extraanatomice find mai puțin traumatice decît cele tradiționale. La pacienții cu traumatisme vasculare associate cu distrucții tisulare adiacente extinse şi plagi cu contaminare bacteriana severă bypassurile extraanatomice sunt de electie. Cu siguranță aceste proceduri trebuie să le posede oricare chirurg vascular.Until now there are no precise criteria regarding the surgical management of extraanatomic by-passes. This incudes indications for surgery, by-pass application techniques and patient selection. The aim of the study is to elucidate this problem, by analyzing the outcomes of 38 patients with extraanatomic by-passes. All patients underwent surgery between 1987-2010. Critical ischaemia of the lower limbs associated with advanced cardiovascular and pulmonary pathology served as indication for the use of extraanatomic by-passes in 21 patients. Another group of 6 patients operated with extraanatomic by-passes had septic processes and 11 patients with vascular injuries associated with bacterial contamination and delabrante wounds. The results mostly depended on the peripheral vascular bed. In patients with critical ischaemia associated with atherosclerosis and advanced cardiovascular and pulmonary disease, or septic processes, the peripheral vascular bed was chronically affected, thus negatively influencing the results – thrombosis of the by-passes in the early postoperative period or after one year occurred in one half of patients. In patients with a satisfactory runoff, all by-passes were patent through all the observation period (from 1 to 11 years). In conclusion the extraanatomic by-passes represent an alternative choice for classical revascularization surgery in some groups of patients, and are the only solution for limb salvage. These interventions are indicated in patients with suppurative processes, to avoid the septic focus. Another group consists of patients with associated advanced cardiovascular and pulmonary pathology, thus the extraanatomic by-passes being less traumatic then the traditional ones. Extraanatomic by-passes are also indicated in cases of vascular injuries associated with bacterial contamination and delabrante wounds. Certainly these are procedures that every vascular surgeon must possess

Revascularization of the infrapopliteal arterial segment in occlusive-stenotic processes

Republica Moldova, IMSP SCR, FPM, Clinica de chirurgie, Secția chirurgie vasculară, Al XI-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” din Republica Moldova și cea de-a XXXIII-a Reuniune a Chirurgilor din Moldova „Iacomi-Răzeșu” 27-30 septembrie 2011Scopul: Studierea rezultatelor precoce ale revascularizărilor chirurgicale a segmentului arterial infrapopliteu în procesele ocluziv-stenotice. Materiale şi metode: Pe parcursul anilor 1995-2010 în secția de Chirurgie Vasculară s-au efectuat 566 de intervenții chirurgicale la 533 pacienți, dintre care 33 la ambele membre inferioare. La 82% pacienți s-a determinat gr III -IV de ischemie la nivelul membrelor inferioare, fapt ce prezintă indicație absolută pentru a interveni chirurgical. Tactica şi volumul operator a fost apreciat conform rezultatelor investigațiilor clinice, duplex scanare, angiografie, CT angiografie şi explorare intraoperatorie. Intervențiile de preferință efectuate au constituit, by-passurile cu grefon safen intern inversat şi trombendarterectomiile din arterele poplitea şi tibială cu petic din autovenă. În 68 (12%) cazuri au fost revascularizate şi segmentele proximale necesitînd by-pass aorto-femural sau femuro-popliteu respectiv. Rezultate: În perioada postoperatorie precoce, retrombozele au survenit în 73 (12,9%) cazuri, dintre care la 28 pacienți datorită reintervențiilor precoce am obținut rezultate favorabile. La 37 pacienți s-a recurs la amputarea coapsei sau gambei. Concluzie: Conform datelor noastre, revascularizarea segmentului arterial infrapopliteu în procesele ocluziv-stenotice este posibilă în 92,5% cazuri. Intervențiile de preferință conform indicațiilor şi investigațiilor efectuate, au constituit by-passurile şi trombendarterectomiile cu folosirea materialului autolog.Aim of the study: Evaluation of early results of surgical revascularization of the infrapopliteal arterial segment in the occlusive-stenotic processes. Material and methods: During the period of 1995-2010 in the Department of Vascular Surgery there have been performed 566 operations in 533 patients, of which 33 for both lower limbs. Critical ischemia was identified in 82% of patients, determining absolute indications for surgery. Further surgical tactics were appreciated after physical examination, duplex scan, angiography, CT angiography and intraoperatory exploration. The elective surgical procedure was by-pass with reversed autologous internal saphenous graft and thrombendarterectomy from the popliteal and tibial arteries with autovenous patch. Proximal segment revascularization using aorto-femoral or femuropopliteal by-passes were necessary in 68 (12%) of cases. Results: The early postoperative period was complicated by rethrombosis in 73 (12,9%) cases. Early reintervention has been performed to 28 patients with satisfactory results. In 37 cases high amputations were necessary. Conclusion: Revascularization of the infrapopliteal arterial segment in occlusive-stenotic processes was possible in 92,5% of cases. The surgical procedures of choice were by-passes and thrombendarterectomy with use of autologous material