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Posachedwapa, nsanja ya antimicrobial yopanda mankhwala yochokera ku nanotechnology pogwiritsa ntchito madzi opangira madzi (EWNS) yapangidwa. EWNS ili ndi chiwongolero chapamwamba kwambiri ndipo ili ndi mitundu yambiri ya okosijeni (ROS) yomwe imatha kuyanjana ndi kuyambitsa tizilombo toyambitsa matenda, kuphatikizapo tizilombo toyambitsa matenda. Apa zikuwonetsedwa kuti katundu wawo panthawi ya kaphatikizidwe amatha kusinthidwa bwino ndikuwongoleredwa kuti apititse patsogolo kuthekera kwawo kwa antibacterial. Pulatifomu ya labotale ya EWNS idapangidwa kuti ikonze bwino zinthu za EWNS posintha magawo a kaphatikizidwe. Makhalidwe a EWNS katundu (charge, size, ndi ROS content) adachitidwa pogwiritsa ntchito njira zamakono zowunikira. Kuonjezera apo, tizilombo toyambitsa matenda monga Escherichia coli, Salmonella enterica, Listeria innocua, Mycobacterium para fortitum, ndi Saccharomyces cerevisiae anathiridwa pamwamba pa tomato wamphesa kuti awone momwe angagwiritsire ntchito tizilombo toyambitsa matenda. Zotsatira zomwe zaperekedwa apa zikuwonetsa kuti katundu wa EWNS akhoza kusinthidwa bwino panthawi ya kaphatikizidwe, zomwe zimapangitsa kuti pakhale kuwonjezeka kwakukulu kwa kusagwira ntchito bwino. Makamaka, mtengo wapamtunda udawonjezeka ndi zina zinayi, ndipo zolemba za ROS zidawonjezeka. Mlingo wochotsa tizilombo tating'onoting'ono udali wodalira pang'ono ndipo udachokera ku 1.0 mpaka 3.8 log pambuyo pa mphindi 45 zokumana ndi mlingo wa aerosol wa 40,000 #/cm3 EWNS.
Kuipitsidwa ndi tizilombo tating'onoting'ono ndizomwe zimayambitsa matenda obwera chifukwa cha zakudya zomwe zimayambitsidwa ndi kuyamwa kwa tizilombo toyambitsa matenda kapena poizoni wawo. Matenda obwera chifukwa cha zakudya amapha anthu pafupifupi 76 miliyoni, ogonekedwa m’chipatala 325,000, ndipo anthu 5,000 amamwalira chaka chilichonse ku United States mokha. Kuwonjezera pamenepo, Dipatimenti Yoona za Ulimi ku United States (USDA) inanena kuti anthu 48 pa 100 alionse amadwala matenda obwera chifukwa cha chakudya ku United States2. Mtengo wa matenda ndi imfa kuchokera ku tizilombo toyambitsa matenda ku United States ndi wokwera kwambiri, malinga ndi Centers for Disease Control and Prevention (CDC) yoposa US $ 15.6 biliyoni pachaka3.
Pakalipano, njira za chemical4, radiation5 ndi thermal6 antimicrobial interventions pofuna kuonetsetsa chitetezo cha chakudya chikutsatiridwa makamaka pa malo ochepa (CCPs) popanga (nthawi zambiri pambuyo pokolola ndi/kapena pakupakira) m'malo mopitirizabe kukhazikitsidwa m'njira yoti zokolola zatsopano zitha kuipitsidwa 7. Njira zolimbana ndi tizilombo toyambitsa matenda zimafunika kuti chakudya chizitha kuwononga bwino komanso kuwononga chakudya chomwe chingathe kuwononga. famu-to-table mosalekeza. Zotsatira zochepa ndi mtengo wake.
Pulogalamu ya nanotechnology yopanda mankhwala oletsa tizilombo toyambitsa matenda yapangidwa posachedwa kuti athetse mabakiteriya pamtunda komanso mumlengalenga pogwiritsa ntchito madzi opangira madzi (EWNS). Kwa kaphatikizidwe ka EVNS, njira ziwiri zofanana zinagwiritsidwa ntchito: electrospray ndi ionization yamadzi (mkuyu 1a). EWNS idawonetsedwa kale kuti ili ndi zida zapadera zakuthupi ndi zachilengedwe8,9,10. EWNS ili ndi ma elekitironi 10 pa dongosolo lililonse ndi kukula kwa nanometer ya 25 nm (Mkuyu 1b, c) 8,9,10. Kuonjezera apo, electron spin resonance (ESR) inasonyeza kuti EWNS ili ndi mitundu yambiri ya okosijeni (ROS), makamaka hydroxyl (OH•) ndi superoxide (O2-) radicals (Mkuyu 1c) 8. EWNS idakhalabe mlengalenga kwa nthawi yayitali ndipo imatha kugundana ndi tizilombo toyambitsa matenda tomwe timayimitsidwa mlengalenga ndikukhalapo pamtunda, kupereka malipiro awo a ROS ndikupangitsa kuti tizilombo toyambitsa matenda tizilombo toyambitsa matenda (mkuyu 1d). Maphunziro oyambirirawa adawonetsanso kuti EWNS imatha kuyanjana ndi kuyambitsa mabakiteriya osiyanasiyana a gram-negative ndi gram-positive ofunika pa thanzi la anthu, kuphatikizapo mycobacteria, pamtunda ndi mu air8,9. Ma electron microscopy adawonetsa kuti kusakhazikikako kudachitika chifukwa cha kusokonezeka kwa nembanemba ya cell. Kuphatikiza apo, kafukufuku wokoka movutikira awonetsa kuti kuchuluka kwa EWNS sikuwononga mapapu kapena kutupa8.
(a) Electrospray imachitika pamene mphamvu yamagetsi ikugwiritsidwa ntchito pakati pa capillary yomwe ili ndi madzi ndi electrode. (b) Kugwiritsa ntchito mphamvu yamagetsi kumabweretsa zochitika ziwiri zosiyana: (i) kupopera madzi ndi electrospraying ndi (ii) kutulutsa mitundu ya okosijeni (yoni) yomwe ili mu EWNS. (c) Mapangidwe apadera a EWNS. (d) EWNS ndi yothamanga kwambiri chifukwa cha chikhalidwe chawo cha nanoscale ndipo imatha kuyanjana ndi tizilombo toyambitsa matenda.
Kuthekera kwa nsanja ya EWNS antimicrobial kuletsa tizilombo toyambitsa matenda pazakudya zatsopano kwawonetsedwanso posachedwa. Zawonetsedwanso kuti mtengo wa EWNS pamwamba ukhoza kugwiritsidwa ntchito limodzi ndi gawo lamagetsi kuti liperekedwe. Chofunika kwambiri, zotsatira zoyambirira zodalirika za kuchepa kwa chipika cha 1.4 mu zochitika za phwetekere organic motsutsana ndi tizilombo tosiyanasiyana tazakudya monga E. coli ndi Listeria zidawonedwa mkati mwa mphindi 90 za EWNS pakusakanikirana kwa pafupifupi 50,000#/cm311. Kuphatikiza apo, mayeso oyambilira a organoleptic adawonetsa kuti palibe zotsatira za organoleptic poyerekeza ndi phwetekere wowongolera. Ngakhale zotsatira zoyambilira za kusakhazikikazi zimalonjeza chitetezo cha chakudya ngakhale pamiyeso yotsika kwambiri ya EWNS ya 50,000 #/cc. onani, zikuwonekeratu kuti kuthekera kwakukulu koyambitsa kutha kukhala kopindulitsa kwambiri kuti muchepetse chiopsezo cha matenda ndi kuwonongeka.
Apa, tiyang'ana pa kafukufuku wathu pakupanga nsanja ya EWNS kuti ikonzenso magawo ophatikizika ndikuwongolera mawonekedwe a physicochemical a EWNS kuti apititse patsogolo kuthekera kwawo kwa antibacterial. Makamaka, kukhathamiritsa kwayang'ana pa kukulitsa mtengo wawo wapamtunda (kuti apititse patsogolo kasamalidwe kamene akuwongolera) ndi zomwe zili mu ROS (kupititsa patsogolo kusagwira ntchito bwino). Makhalidwe abwino a physico-chemical properties (kukula, mtengo ndi ROS content) pogwiritsa ntchito njira zamakono zowunikira ndi kugwiritsa ntchito tizilombo toyambitsa matenda monga E. coli, S. enterica, L. innocua, S. cerevisiae ndi M. parafortuitum.
EVNS inapangidwa ndi electrospraying panthawi imodzi ndi ionization ya madzi oyera kwambiri (18 MΩ cm-1). Atomizer yamagetsi 12 imagwiritsidwa ntchito kupangira atomize zakumwa ndi polima zopangira ndi ceramic particles 13 ndi ulusi 14 wa kukula kwake.
Monga momwe zafotokozedwera m'mabuku am'mbuyomu 8, 9, 10, 11, pakuyesa wamba, mphamvu yamagetsi yayikulu imayikidwa pakati pa capillary yachitsulo ndi electrode yotsatsira. Panthawiyi, zochitika ziwiri zosiyana zimachitika: 1) electrospray ndi 2) ionization ya madzi. Munda wamagetsi wamphamvu pakati pa maelekitirodi awiriwa umapangitsa kuti mitengo yoyipa ipangike pamwamba pamadzi opindika, zomwe zimapangitsa kuti ma cone a Taylor apangidwe. Zotsatira zake, madontho amadzi odzaza kwambiri amapangidwa, omwe amapitirizabe kusweka kukhala tinthu tating'onoting'ono, malinga ndi chiphunzitso cha Rayleigh16. Nthawi yomweyo, mphamvu yamagetsi yamphamvu imapangitsa kuti mamolekyu ena amadzi agawike ndikuchotsa ma electron (ionization), motero amapanga mitundu yambiri ya okosijeni (ROS)17. Imodzi kwaiye ROS18 mapaketi anali encapsulated EWNS (mkuyu. 1c).
Pa mkuyu. 2a ikuwonetsa dongosolo la m'badwo wa EWNS lopangidwa ndikugwiritsidwa ntchito mu kaphatikizidwe ka EWNS mu kafukufukuyu. Madzi oyeretsedwa osungidwa mu botolo lotsekedwa amadyetsedwa kudzera mu chubu cha Teflon (2 mm mkati mwake) mpaka 30G singano yachitsulo chosapanga dzimbiri (chitsulo capillary). Monga momwe chithunzi 2b chikusonyezera, kutuluka kwa madzi kumayendetsedwa ndi kuthamanga kwa mpweya mkati mwa botolo. Singano imamangiriridwa ku cholembera cha Teflon chomwe chingasinthidwe pamanja mtunda wina kuchokera pamagetsi amagetsi. The counter electrode ndi opukutidwa aluminiyamu litayamba ndi dzenje pakati pa zitsanzo. Pansi pa kauntala elekitirodi ndi aluminiyamu sampling funnel, amene olumikizidwa kwa ena khwekhwe kuyesera kudzera doko chitsanzo (mkuyu. 2b). Zigawo zonse za sampler zimakhazikika pamagetsi kuti zisamangidwenso zomwe zingawononge kusanja kwa tinthu.
(a) Engineered Water Nanostructure Generation System (EWNS). (b) Cross gawo la sampler ndi electrospray unit yomwe ikuwonetsa magawo ofunikira kwambiri. (c) Kukonzekera koyeserera koyambitsa mabakiteriya.
Dongosolo la EWNS lomwe lafotokozedwa pamwambapa limatha kusintha magawo ogwiritsira ntchito kuti athandizire kukonza bwino kwa katundu wa EWNS. Sinthani mphamvu yogwiritsira ntchito (V), mtunda wa pakati pa singano ndi electrode ya counter (L), ndi kutuluka kwa madzi (φ) kupyolera mu capillary kuti mukonze bwino makhalidwe a EWNS. Zizindikiro [V (kV), L (cm)] zimagwiritsidwa ntchito kutanthauza kuphatikizika kosiyanasiyana. Sinthani kayendedwe ka madzi kuti mupeze khola lokhazikika la Taylor la seti inayake [V, L]. Pazolinga za phunziroli, kabowo ka kauntala elekitirodi (D) adayikidwa pa mainchesi 0.5 (1.29 cm).
Chifukwa cha zochepa za geometry ndi asymmetry, mphamvu yamagetsi yamagetsi sangathe kuwerengedwa kuchokera ku mfundo zoyambirira. M'malo mwake, pulogalamu ya QuickField™ (Svendborg, Denmark)19 idagwiritsidwa ntchito kuwerengera gawo lamagetsi. Munda wamagetsi siwofanana, kotero kuti mtengo wamagetsi pamphepete mwa capillary unagwiritsidwa ntchito ngati chidziwitso cha masanjidwe osiyanasiyana.
Pa kafukufukuyu, mitundu ingapo ya ma voltage ndi mtunda pakati pa singano ndi ma electrode owerengera adawunikidwa malinga ndi mapangidwe a Taylor cone, Taylor cone kukhazikika, kukhazikika kwa kupanga kwa EWNS, komanso kuberekana. Kuphatikizika kosiyanasiyana kumawonetsedwa mu Supplementary Table S1.
Kutulutsa kwa kachitidwe ka mtundu wa EWNS kudalumikizidwa mwachindunji ndi Scanning Mobility Particle Sizer (SMPS, model 3936, TSI, Shoreview, Minnesota) kuyeza kuchuluka kwa nambala ya tinthu ndipo idagwiritsidwa ntchito ndi faraday aerosol electrometer (TSI, model 3068B, Shoreview, USA). MN) kuyeza kuyenda kwa aerosol, monga tafotokozera m'buku lathu lapitalo9. Zonse za SMPS ndi electrometer ya aerosol zomwe zimatengedwa pamtunda wa 0.5 L/mphindi (chitsanzo chonse chotuluka 1 L/mphindi). Kuchuluka kwa tinthu tating'onoting'ono komanso kutulutsa kwa aerosol kumayesedwa kwa 120 s. Bwerezani muyeso 30 nthawi. Mtengo wonse wa aerosol umawerengeredwa kuchokera mumiyezo yapano, ndipo pafupifupi mtengo wa EWNS umayerekezedwa kuchokera ku chiwerengero chonse cha tinthu ta EWNS totengedwa. Mtengo wapakati wa EWNS ukhoza kuwerengedwa pogwiritsa ntchito Equation (1):
kumene IEl ndi yomwe imayezedwa panopa, NSMPS ndi chiwerengero cha chiwerengero choyesedwa ndi SMPS, ndipo φEl ndi mlingo wothamanga kupita ku electrometer.
Chifukwa chinyezi chachibale (RH) chimakhudza mtengo wa pamwamba, kutentha ndi (RH) zinkasungidwa nthawi zonse pa 21 ° C ndi 45%, motero, panthawi yoyesera.
Atomic force microscopy (AFM), Asylum MFP-3D (Asylum Research, Santa Barbara, CA) ndi AC260T probe (Olympus, Tokyo, Japan) anagwiritsidwa ntchito poyeza kukula ndi moyo wa EWNS. Mlingo wa sikani wa AFM ndi 1 Hz ndipo malo ojambulira ndi 5 µm×5 µm okhala ndi mizere yojambulira 256. Zithunzi zonse zidapangidwa kuti zigwirizane ndi mawonekedwe oyamba pogwiritsa ntchito pulogalamu ya Asylum (chigoba chokhala ndi 100 nm ndi 100 pm).
Chotsani chitsanzo cha faniyo ndikuyika mica pamwamba pa mtunda wa 2.0 masentimita kuchokera pa kauntala elekitirodi kwa nthawi pafupifupi 120 s kupewa coalescence wa particles ndi mapangidwe osakhazikika m'malovu pa mica pamwamba. EWNS idagwiritsidwa ntchito mwachindunji kumalo odulidwa kumene a mica (Ted Pella, Redding, CA). Atangotulutsa, ma mica pamwamba adawonetsedwa pogwiritsa ntchito AFM. Kulumikizana kwapamtunda kwa mica yosasinthidwa kumene kuli pafupi ndi 0 °, kotero EWNS imafalikira pamwamba pa mica mu mawonekedwe a domed20. M'mimba mwake (a) ndi kutalika (h) kwa madontho osakanikirana adayezedwa mwachindunji kuchokera ku AFM topography ndipo amagwiritsidwa ntchito kuwerengera kuchuluka kwa voliyumu ya EWNS pogwiritsa ntchito njira yathu yovomerezeka kale8. Pongoganiza kuti EVNS yomwe ili m'bwalo ili ndi voliyumu yofanana, kukula kofananako kumatha kuwerengedwa kuchokera ku equation (2):
Mogwirizana ndi njira yathu yomwe tapanga kale, msampha wa electron spin resonance (ESR) unagwiritsidwa ntchito kuti azindikire kukhalapo kwapakati pa nthawi yochepa mu EWNS. Ma aerosols adadutsa mu yankho lomwe lili ndi 235 mM DEPMPO (5-(diethoxyphosphoryl) -5-methyl-1-pyrroline-N-oxide) (Oxis International Inc., Portland, Oregon). Miyezo yonse ya EPR inkagwiritsidwa ntchito pogwiritsa ntchito Bruker EMX spectrometer (Bruker Instruments Inc. Billerica, MA, USA) ndi ma cell arrays. Pulogalamu ya Acquisit (Bruker Instruments Inc. Billerica, MA, USA) inagwiritsidwa ntchito kusonkhanitsa ndi kusanthula deta. Makhalidwe a ROS adachitidwa pokhapokha pazigawo zogwirira ntchito [-6.5 kV, 4.0 cm]. Zolinga za EWNS zidayesedwa pogwiritsa ntchito SMPS pambuyo poganizira kutayika kwa EWNS mu impactor.
Miyezo ya ozoni idawunikidwa pogwiritsa ntchito 205 Dual Beam Ozone Monitor™ (2B Technologies, Boulder, Co)8,9,10.
Pazinthu zonse za EWNS, muyeso woyezera ndiye tanthawuzo la miyeso, ndipo cholakwika cha muyeso ndichopatuka kokhazikika. Kuyesa kwa t kunachitika kuti kufananize mtengo wa mawonekedwe a EWNS okongoletsedwa ndi mtengo wofananira wa maziko a EWNS.
Chithunzi 2c chikuwonetsa njira yomwe idapangidwa kale komanso yodziwika bwino ya Electrostatic Precipitation Pass Through System (EPES) yomwe ingagwiritsidwe ntchito kutsata EWNS11 pamalo. EPES amagwiritsa ntchito EWNS charge kuphatikiza ndi malo amagetsi amphamvu kuti "akuloze" molunjika pamalo omwe chandamale. Tsatanetsatane wa dongosolo la EPES likuperekedwa m'buku laposachedwapa la Pyrgiotakis et al.11. Chifukwa chake, EPES imakhala ndi chipinda cha PVC chosindikizidwa cha 3D chokhala ndi malekezero opindika okhala ndi zitsulo ziwiri zofanana (304 zitsulo zosapanga dzimbiri, galasi lopukutidwa) mbale zachitsulo pakati pa 15.24 cm motalikirana. Ma board anali olumikizidwa ku gwero lamphamvu lamagetsi lakunja (Bertran 205B-10R, Spellman, Hauppauge, NY), bolodi yapansi nthawi zonse inali yabwino ndipo bolodi lapamwamba nthawi zonse limakhala pansi (loyandama). Makoma a chipindacho amaphimbidwa ndi zojambulazo za aluminiyamu, zomwe zimakhala ndi magetsi kuti zisawonongeke. Chipindacho chili ndi chitseko chotsekera chakutsogolo chomwe chimalola kuti malo oyeserera ayikidwe pazitsulo zapulasitiki, kuwachotsa pansi pazitsulo zachitsulo kuti asasokonezedwe ndi magetsi ambiri.
Kugwiritsa ntchito bwino kwa EWNS mu EPES kunawerengedwa molingana ndi protocol yomwe idapangidwa kale yofotokozedwa mu Supplementary Figure S111.
Monga chipinda cholamulira, kuyenda kwachiwiri kupyolera mu chipinda cha cylindrical kumalumikizidwa mndandanda ndi dongosolo la EPES pogwiritsa ntchito fyuluta yapakatikati ya HEPA kuchotsa EWNS. Monga momwe tawonetsera mkuyu. 2c, aerosol ya EWNS idapopedwa kudzera m'zipinda ziwiri zolumikizidwa motsatizana. Fyuluta pakati pa chipinda chowongolera ndi EPES imachotsa EWNS iliyonse yotsalira chifukwa cha kutentha komweko (T), chinyezi chapafupi (RH) ndi ma ozone.
Tizilombo toyambitsa matenda tomwe timapezeka m'zakudya tapezeka kuti tiyipitsa zokolola zatsopano monga Escherichia coli (ATCC #27325), chizindikiro cha fecal, Salmonella enterica (ATCC #53647), tizilombo toyambitsa matenda, Listeria innocua (ATCC #33090), m'malo mwa pathogenic Listeria monocy. , Saccharomyces cerevisiae (ATCC #4098) ngati m'malo mwa yisiti yowonongeka, ndi Mycobacterium parafortuitous (ATCC #19686) monga mabakiteriya olimbana ndi moyo adagulidwa ku ATCC (Manassas, Virginia).
Mwachisawawa gulani mabokosi a tomato wamphesa kuchokera kumsika wapafupi ndi kwanu ndikusunga mufiriji pa 4°C mpaka mugwiritse ntchito (mpaka masiku atatu). Sankhani tomato kuti muyese kukula kwake, pafupifupi 1/2 inchi m'mimba mwake.
Ma protocol a incubation, inoculation, exposure and colony counting akhala akufotokozedwa mwatsatanetsatane m'mabuku athu apitalo ndipo adafotokozedwa mwatsatanetsatane mu Supplementary Data 11. Kuchita kwa EWNS kunayesedwa powonetsa tomato wopangidwa ndi 40,000 #/cm3 kwa mphindi 45. Mwachidule, panthawi t = 0 min, tomato atatu adagwiritsidwa ntchito poyesa tizilombo tokhalapo. Tomato atatu adayikidwa mu EPES ndipo adawonekera kwa EWNS pa 40,000 # / cc (EWNS poyera tomato) ndipo ena atatu adayikidwa mu chipinda chowongolera (tomato control). Palibe gulu lililonse la phwetekere lomwe lidapangidwanso. Tomato ndi zowongolera za EWNS zidachotsedwa pambuyo pa mphindi 45 kuti ziwone zotsatira za EWNS.
Kuyesera kulikonse kunkachitika katatu. Kusanthula kwa data kunachitika molingana ndi protocol yofotokozedwa mu Supplementary Data.
E. coli, Enterobacter, ndi L. innocua mabakiteriya zitsanzo zowululidwa kwa EWNS (45 min, EWNS aerosol concentration 40,000 #/cm3) ndi zosaonekera anali pellets kuona inactivation njira. Mphepoyi inakhazikitsidwa kwa maola a 2 kutentha kwa 0.1 M sodium cacodylate solution (pH 7.4) ndi fixative ya 2.5% glutaraldehyde, 1.25% paraformaldehyde ndi 0.03% picric acid. Atatha kutsuka, adayikidwa ndi 1% osmium tetroxide (OsO4) / 1.5% potassium ferrocyanide (KFeCN6) kwa 2 h, kutsukidwa katatu ndi madzi ndikuyika mu 1% uranyl acetate kwa 1 h, kenako kutsukidwa kawiri ndi madzi. Kutaya madzi m'thupi kwa mphindi 10 aliyense wa 50%, 70%, 90%, 100% mowa. Zitsanzozo zinayikidwa mu propylene oxide kwa ola la 1 ndikuyika ndi 1: 1 osakaniza a propylene oxide ndi TAAP Epon (Marivac Canada Inc. St. Laurent, CA). Zitsanzozo zidaphatikizidwa mu TAAB Epon ndikupangidwa ndi polymer pa 60 ° C kwa maola 48. Utoto wochiritsidwa wochiritsidwawo unadulidwa ndikuwonetseredwa ndi TEM pogwiritsa ntchito JEOL 1200EX (JEOL, Tokyo, Japan), maikulosikopu wamba yamagetsi yokhala ndi kamera ya AMT 2k CCD (Advanced Microscopy Techniques, Corp., Woburn, MA, USA).
Zoyesera zonse zidachitika mwapatatu. Pa nthawi iliyonse, mabakiteriya amatsuka katatu, zomwe zinapangitsa kuti pakhale mfundo zisanu ndi zinayi pa mfundo iliyonse, pafupifupi yomwe imagwiritsidwa ntchito ngati mabakiteriya a chamoyocho. Kupatuka kokhazikika kunagwiritsidwa ntchito ngati cholakwika choyezera. Mfundo zonse zimawerengera.
Logarithm ya kuchepa kwa kuchuluka kwa mabakiteriya poyerekeza ndi t = 0 min idawerengedwa pogwiritsa ntchito njira iyi:
kumene C0 ndi kuchuluka kwa mabakiteriya mu chitsanzo chowongolera pa nthawi 0 (ie pambuyo pouma pamwamba koma asanaikidwe m'chipinda) ndipo Cn ndi kuchuluka kwa mabakiteriya pamtunda pambuyo pa n maminiti akuwonekera.
Kuwerengera kuwonongeka kwachilengedwe kwa mabakiteriya munthawi ya mphindi ya 45, Log-Reduction idawerengedwanso poyerekeza ndi kuwongolera kwa mphindi 45 motere:
Kumene Cn ndi kuchuluka kwa mabakiteriya mu chitsanzo chowongolera panthawi n ndi Cn-Control ndi kuchuluka kwa mabakiteriya olamulira panthawi n. Deta imaperekedwa ngati kuchepetsedwa kwa chipika poyerekeza ndi kuwongolera (palibe kuwonekera kwa EWNS).
Pa kafukufukuyu, mitundu ingapo ya ma voltage ndi mtunda pakati pa singano ndi ma electrode owerengera adawunikidwa malinga ndi mapangidwe a Taylor cone, Taylor cone kukhazikika, kukhazikika kwa kupanga kwa EWNS, komanso kuberekana. Kuphatikizika kosiyanasiyana kumawonetsedwa mu Supplementary Table S1. Milandu iwiri idasankhidwa kuti ifufuze kwathunthu yowonetsa zinthu zokhazikika komanso zopangika (Taylor cone, kupanga kwa EWNS, ndi kukhazikika pakapita nthawi). Pa mkuyu. 3 ikuwonetsa zotsatira pa mtengo, kukula ndi zomwe zili mu ROS pamilandu iwiri. Zotsatirazo zikufotokozedwanso mwachidule mu Table 1. Pofotokoza, Chithunzi 3 ndi Table 1 zikuphatikizapo katundu wa EWNS8, 9, 10, 11 (zoyambira-EWNS) zomwe zinapangidwa kale. Kuwerengera kufunikira kowerengera pogwiritsa ntchito kuyesa kwa michira iwiri kumasindikizidwanso mu Supplementary Table S2. Kuonjezera apo, deta yowonjezera imaphatikizapo maphunziro okhudza momwe ma electrode sampling hole diameter (D) ndi mtunda wapakati pa electrode yapansi ndi nsonga ya singano (L) (Supplementary Figures S2 ndi S3).
(a–c) Kugawa kwa kukula kwa AFM. (d – f) Mawonekedwe a pamwamba. (g) Makhalidwe a ROS ndi ESR.
Ndikofunikiranso kuzindikira kuti pazonse zomwe tafotokozazi, mafunde a ionization omwe amayezedwa anali mumtundu wa 2-6 µA, ndipo ma voltages anali mumtundu wa -3.8 mpaka -6.5 kV, zomwe zidapangitsa kugwiritsa ntchito mphamvu kwa EWNS yamtundu umodzi wochepera 50 mW. . Generation module. Ngakhale kuti EWNS idapangidwa mopanikizika kwambiri, milingo ya ozone inali yotsika kwambiri, yosapitilira 60 ppb.
Supplementary Figure S4 ikuwonetsa magawo amagetsi ofananirako a [-6.5 kV, 4.0 cm] ndi [-3.8 kV, 0.5 cm] motsatana. Minda malinga ndi zochitika [-6.5 kV, 4.0 cm] ndi [-3.8 kV, 0.5 cm] amawerengedwa ngati 2 × 105 V/m ndi 4.7 × 105 V/m, motero. Izi ziyenera kuyembekezera, popeza chiŵerengero cha magetsi ndi mtunda chimakhala chokwera kwambiri pazochitika zachiwiri.
Pa mkuyu. 3a,b ikuwonetsa kukula kwa EWNS kuyesedwa ndi AFM8. Avareji ma diameter a EWNS a [-6.5 kV, 4.0 cm] ndi [-3.8 kV, 0.5 cm] amawerengeredwa ngati 27 nm ndi 19 nm, motsatana. Kupatuka kwa geometric kumagawidwe amilandu [-6.5 kV, 4.0 cm] ndi [-3.8 kV, 0.5 cm] ndi 1.41 ndi 1.45, motsatana, kuwonetsa kugawa kocheperako. Kusiyanitsa kwakukulu ndi mawonekedwe a geometric ali pafupi kwambiri ndi chiyambi-EWNS, pokhala 25 nm ndi 1.41, motsatira. Pa mkuyu. 3c ikuwonetsa kugawidwa kwa kukula kwa EWNS yoyambira yoyezedwa pogwiritsa ntchito njira yomweyo pansi pamikhalidwe yomweyi.
Pa mkuyu. 3d, e ikuwonetsa zotsatira za mawonekedwe amalipiro. Deta ndi miyeso yapakati ya 30 miyeso yokhazikika nthawi imodzi (#/cm3) ndi yapano (I). Kusanthula kukuwonetsa kuti mtengo wapakati pa EWNS ndi 22 ± 6 e- ndi 44 ± 6 e- kwa [-6.5 kV, 4.0 cm] ndi [-3.8 kV, 0.5 cm], motero. Poyerekeza ndi Baseline-EWNS (10 ± 2 e-), mtengo wawo wapamtunda ndi wapamwamba kwambiri, wowirikiza kawiri wa mawonekedwe a [-6.5 kV, 4.0 cm] ndi kanayi kuposa [-3 .8 kV, 0.5 cm]. 3f ikuwonetsa zoyambira zolipira za EWNS.
Kuchokera pamapu owerengera manambala a EWNS (Ziwerengero Zowonjezera S5 ndi S6), zitha kuwoneka kuti [-6.5 kV, 4.0 cm] chowonekera chili ndi tinthu tambirimbiri kuposa [-3.8 kV, 0.5 cm] powonekera. Tiyeneranso kukumbukira kuti chiwerengero cha chiwerengero cha EWNS chinayang'aniridwa kwa maola a 4 (Supplementary Figures S5 ndi S6), kumene kukhazikika kwa mbadwo wa EWNS kunasonyeza milingo yofanana ya chiwerengero cha tinthu pazochitika zonsezi.
Chithunzi 3g chikuwonetsa mawonekedwe a EPR pambuyo pakuwongolera (kumbuyo) kwa EWNS yokometsedwa pa [-6.5 kV, 4.0 cm]. Mawonekedwe a ROS amafananizidwanso ndi maziko a EWNS mu pepala lofalitsidwa kale. Nambala yowerengedwa ya EWNS ikuchita ndi msampha wozungulira ndi 7.5 × 104 EWNS/s, yomwe ili yofanana ndi yomwe idasindikizidwa kale Baseline-EWNS8. Mawonekedwe a EPR adawonetsa momveka bwino kukhalapo kwa mitundu iwiri ya ROS, pomwe O2- inali yotsogola, pomwe OH• inalipo pang'ono. Kuphatikiza apo, kuyerekeza kwachindunji kwamphamvu kwambiri kunawonetsa kuti EWNS yokongoletsedwa inali ndi ROS yapamwamba kwambiri poyerekeza ndi EWNS yoyambira.
Pa mkuyu. 4 ikuwonetsa magwiridwe antchito a EWNS mu EPES. Zomwe zimafotokozedwanso mwachidule mu Table I ndikufaniziridwa ndi deta yoyambirira ya EWNS. Pamilandu yonse ya EUNS, kuyika kunali pafupi ndi 100% ngakhale pamagetsi otsika a 3.0 kV. Nthawi zambiri, 3.0 kV ndi yokwanira kukwaniritsa 100% mosasamala kanthu za kusintha kwa mtengo wapamtunda. Pansi pamikhalidwe yomweyi, magwiridwe antchito a Baseline-EWNS anali 56% okha chifukwa cha mtengo wotsika (pafupifupi ma electron 10 pa EWNS).
Chithunzi 5 ndi Table 2 mwachidule mlingo wa inactivation wa tizilombo inoculated padziko tomato pambuyo kukhudzana pafupifupi 40,000 #/cm3 EWNS kwa mphindi 45 pansi mulingo woyenera kwambiri nkhani [-6.5 kV, 4.0 cm]. E. coli ya E. coli ndi L. innocua inasonyeza kuchepa kwakukulu kwa chipika cha 3.8 pambuyo pa mphindi 45 zowonekera. Pansi pazikhalidwe zomwezo, S. enterica inasonyeza kuchepa kwa chipika cha 2.2, pamene S. cerevisiae ndi M. parafortuitum adawonetsa kutsika kwa chipika cha 1.0.
Electron micrographs (Chithunzi 6) chosonyeza kusintha kwa thupi komwe kunayambitsidwa ndi EWNS mu E. coli, Salmonella enterica, ndi maselo a L. innocua omwe amatsogolera ku innocua. Mabakiteriya owongolera adawonetsa ma cell a cell, pomwe mabakiteriya owonekera adawononga nembanemba zakunja.
Kujambula kwa electron microscopic kulamulira ndi mabakiteriya owonekera kunavumbula kuwonongeka kwa nembanemba.
Deta ya physicochemical properties of optimized EWNS pamodzi imasonyeza kuti katundu wa EWNS (surface charge ndi ROS content) anali bwino kwambiri poyerekeza ndi EWNS yofalitsidwa kale deta8,9,10,11. Kumbali ina, kukula kwawo kunakhalabe mumtundu wa nanometer, womwe uli wofanana kwambiri ndi zotsatira zomwe zidasindikizidwa kale, zomwe zimawalola kukhala mlengalenga kwa nthawi yaitali. Ma polydispersity omwe adawonedwa amatha kufotokozedwa ndi kusintha kwamphamvu kwapamtunda, komwe kumatsimikizira kukula kwa Rayleigh effect, randomness, ndi kuthekera kophatikizana kwa EWNS. Komabe, monga momwe Nielsen et al.22 adafotokozera, mtengo wapamwamba wa pamwamba umachepetsa evaporation powonjezera mphamvu ya pamwamba / kuthamanga kwa madzi. Chiphunzitsochi chinatsimikiziridwa moyesera za microdroplets22 ndi EWNS m'buku lathu lapitalo8. Kutayika kwa nthawi yowonjezera kungakhudzenso kukula ndikuthandizira kugawidwa kwa kukula komwe kumawonedwa.
Komanso, mlandu pa dongosolo ndi za 22-44 e-, malingana ndi mikhalidwe, amene ndi apamwamba kwambiri poyerekeza ndi EWNS zofunika, amene ali pafupifupi mlandu wa 10 ± 2 ma elekitironi pa dongosolo. Komabe, ziyenera kudziwidwa kuti awa ndiye mtengo wapakati wa EWNS. Seto et al. Zasonyezedwa kuti ndalamazo sizili zofanana ndipo zimatsatira kugawa kwachizolowezi21. Poyerekeza ndi ntchito yathu yam'mbuyomu, kuwirikiza kawiri kuchuluka kwapamwamba kumachulukitsa kuchuluka kwa magwiridwe antchito mu dongosolo la EPES mpaka pafupifupi 100% 11.