Enhanced catalytic reduction through in situ synthesized gold nanoparticles embedded in glucosamine/alginate nanocomposites

• Chi-Hien Dang,
• Le-Kim-Thuy Nguyen,
• Minh-Trong Tran,
• Van-Dung Le,
• Nguyen Minh Ty,
• T. Ngoc Han Pham,
• Hieu Vu-Quang,
• Tran Thi Kim Chi,
• Tran Thi Huong Giang,
• Nguyen Thi Thanh Tu and
• Thanh-Danh Nguyen

Beilstein J. Nanotechnol. 2024, 15, 1227–1237, doi:10.3762/bjnano.15.99

• g·mL−1). The reduction process was initiated through heating the mixture and visually confirmed by a change in color of the reaction mixture indicating the formation of AuNPs on the GluN/Alg composite. UV–vis spectroscopy within the range of 300 to 600 nm was employed to monitor this process

• ) using a nanoPartica Horiba SZ-100 instrument. Thermal analysis through thermogravimetry (TGA) was performed using a LabSys evo S60/58988 Thermoanalyzer (Setaram, France). The oven-dried powder of both blank nanocomposite GluN/Alg and synthesized composite AuNPs@GluN/Alg underwent heating from 30 to 800

• within the composite. The highly negative zeta potentials of both nanocomposites indicated their high stability in the aqueous solution. The functional groups present in the nanocomposite were identified through FTIR spectroscopy, with the blank nanocomposite serving as a reference for the analysis of

Photocatalytic methane oxidation over a TiO₂/SiNWs p–n junction catalyst at room temperature

• Qui Thanh Hoai Ta,
• Luan Minh Nguyen,
• Ngoc Hoi Nguyen,
• Phan Khanh Thinh Nguyen and
• Dai Hai Nguyen

Beilstein J. Nanotechnol. 2024, 15, 1132–1141, doi:10.3762/bjnano.15.92

• formed at the interface have emerged, which effectively force charge carriers to move in opposite directions and hinder recombination [31][32][33]. Very recently, Cu2O/BiVO4, Ag2O/Bi12O17Cl2 and CuFe2O4/Bi4Ti3O12 composite powders have shown improved efficiencies in water treatment based on p–n

• phase (JCPDS No.27-1402) [40][41]. In the case of the as-synthesized composite, the favored growth of TiO2(101) on the surface of p-Si NWs has been noticed [42]. The minor (112), (200), (105), and (211) peaks at 2θ = 38.2°, 48.5°, 53.3°, and 55.1° indicate the formation of anatase TiO2 (JCPDS No.21-1272

• ). Although the TiO2/Si composite did not achieve the best results compared to other photocatalysts, it remains a viable option for methane oxidation processes. In order to investigate the individual effects of p-type SiNWs and TiO2 layer on the photocatalytic OCM efficiency, comparable samples were

Unveiling the potential of alginate-based nanomaterials in sensing technology and smart delivery applications

• Shakhzodjon Uzokboev,
• Khojimukhammad Akhmadbekov,
• Ra’no Nuritdinova,
• Salah M. Tawfik and
• Yong-Ill Lee

Beilstein J. Nanotechnol. 2024, 15, 1077–1104, doi:10.3762/bjnano.15.88

• -based composite nanoparticles, which provides a comprehensive overview of nanoparticles and their uses, especially in sensing applications (Figure 2). Moreover, characterization techniques of biopolymeric nanoparticles and their importance for drug delivery and sensing methods will be reviewed. In

• kilohertz. Another alginate-based humidity sensor is carbonized lignin-loaded sodium alginate (CL/SA). The CL/SA composite film provided extremely high sensitivity, low hysteresis, and consistent repeatability throughout a wide relative humidity range of 11–97%. Furthermore, the CL/SA sensor allowed for

• measuring human breathing. According to the results, CL/SA composite is a good humidity-sensitive material [125]. However, further research is needed to fully understand and optimize the properties of alginate-based nanoparticles for environmental sensing. Future studies should focus on optimizing the

Interface properties of nanostructured carbon-coated biological implants: an overview

• Mattia Bartoli,
• Francesca Cardano,
• Erik Piatti,
• Stefania Lettieri,
• Andrea Fin and
• Alberto Tagliaferro

Beilstein J. Nanotechnol. 2024, 15, 1041–1053, doi:10.3762/bjnano.15.85

• Young’s modulus of 100% and 156%, reaching 60 MPa and 0.52 GPa, respectively, after coating. CNTs are generally used to reinforce the bulk of composite-based implants [136] or added to polymeric films [135]. Interestingly, they can be mixed with hydroxyapatite in order to magnify the compatibility with

Beyond biomimicry – next generation applications of bioinspired adhesives from microfluidics to composites

• Dan Sameoto

Beilstein J. Nanotechnol. 2024, 15, 965–976, doi:10.3762/bjnano.15.79

• degree of controllability or even its ability to self-support under gravitational loads; thus, there is a major interest in stiffness-tunable materials for soft robotic systems [15]. This stiffness tuning in many cases relies on the temporary bonding of composite layers or materials to change effective

• in fact be best suited as the internal surface of a composite material sparked a new and exciting research direction for soft robotics and adaptable composites. The reasons to use these materials as an internal rather than an external surface can be broadly categorized as follows: Uniform contact

• surfaces: Unlike a gecko, the adhesive materials do not need to be overdesigned for potentially touching dirty, rough, wet surfaces but can always be in contact with an ideally suited surface. No contaminants: When contained within a composite, these adhesives can be almost entirely free of contaminants

Electrospun nanofibers: building blocks for the repair of bone tissue

• Tuğrul Mert Serim,
• Gülin Amasya,
• Tuğba Eren-Böncü,
• Ceyda Tuba Şengel-Türk and
• Ayşe Nurten Özdemir

Beilstein J. Nanotechnol. 2024, 15, 941–953, doi:10.3762/bjnano.15.77

• surrounding muscle tissue as well. It plays an important role in bone growth and fracture healing [18][19]. The composition of bone tissue Any bone in the body has both an organic and inorganic composite structure. The composition of extracellular bone matrix can be estimated as approximately 60–65% organic

A review on the structural characterization of nanomaterials for nano-QSAR models

• Salvador Moncho,
• Eva Serrano-Candelas,
• Jesús Vicente de Julián-Ortiz and
• Rafael Gozalbes

Beilstein J. Nanotechnol. 2024, 15, 854–866, doi:10.3762/bjnano.15.71

• , which can be classified according to their chemical composition in inorganic, carbon-based, organic, and composite NMs (Figure 4). In organic molecules, a wide range of descriptors are obtained from the topology of the molecule, arising from the rich variety of structural motifs that can be found and

Intermixing of MoS₂ and WS₂ photocatalysts toward methylene blue photodegradation

• Maryam Al Qaydi,
• Nitul S. Rajput,
• Michael Lejeune,
• Abdellatif Bouchalkha,
• Mimoun El Marssi,
• Steevy Cordette,
• Chaouki Kasmi and
• Mustapha Jouiad

Beilstein J. Nanotechnol. 2024, 15, 817–829, doi:10.3762/bjnano.15.68

• several cycles. This finding underscores the advantageous outcomes of intermixing WS2 and MoS2, shedding light on the development of an efficient and enduring photocatalyst for visible-light-driven photodegradation of methylene blue. Keywords: methylene blue; MoS2/WS2 composite; photocatalysis

• , with over 99% degradation of MB achieved within 60 min under visible light exposure by using 10 mg of the catalyst to degrade 10 mg/L of MB [22]. Other works have shown that the MoS2–ZnO composite achieved 97% of MB photodegradation in ≈30 min under visible irradiation by using 250 mg/L of the catalyst

• 410 cm−1, respectively, for MoS2, 350 cm−1. It can be further resolved into two sub-peaks at 324 cm−1 and 351 cm−1, corresponding to the 2LA(M) and E12g modes, the A1g mode at 420 cm−1 for WS2, and the presence of combined vibration modes for the composite MoS2/WS2 as shown in Figure 1. Interestingly

Electrospun polysuccinimide scaffolds containing different salts as potential wound dressing material

• Veronika Pálos,
• Krisztina S. Nagy,
• Rita Pázmány,
• Krisztina Juriga-Tóth,
• Bálint Budavári,
• Judit Domokos,
• Dóra Szabó,
• Ákos Zsembery and
• Angela Jedlovszky-Hajdu

Beilstein J. Nanotechnol. 2024, 15, 781–796, doi:10.3762/bjnano.15.65

• easily linked to the polymer or distributed to them in the same solvent; thus, a multicomponent composite system can be generated. Based on the parameters mentioned above, wound-dressing application is one of the most relevant research areas for these systems [7]. An effective wound dressing should

• ][37]. This study aimed to create a two-component polymer-composite scaffold as a potential wound dressing material by electrospinning, using antibacterial salts (Zn(O2CCH3)2 or Sr(NO3)2) in addition to PSI. We performed the following experiments: physical and chemical characterization of the fibers by

• note that the Kruskal–Wallis test shows significant differences between groups when not only the medians and variances differ but also when the shape of the distribution is different. According to another survey where another polymer composite (polyacrylonitrile/polyvinylidene fluoride) containing

Simultaneous electrochemical determination of uric acid and hypoxanthine at a TiO₂/graphene quantum dot-modified electrode

• Vu Ngoc Hoang,
• Dang Thi Ngoc Hoa,
• Nguyen Quang Man,
• Le Vu Truong Son,
• Le Van Thanh Son,
• Vo Thang Nguyen,
• Le Thi Hong Phong,
• Ly Hoang Diem,
• Kieu Chan Ly,
• Ho Sy Thang and
• Dinh Quang Khieu

Beilstein J. Nanotechnol. 2024, 15, 719–732, doi:10.3762/bjnano.15.60

• composite (TiO2/GQDs) obtained by in situ synthesis of GQDs, derived from coffee grounds, and peroxo titanium complexes was used as electrode modifier in the simultaneous electrochemical determination of uric acid and hypoxanthine. The TiO2/GQDs material was characterized by photoluminescence, X-ray

• nm that consist of fine nanoparticles (Figure 3a), while that of GQDs shows fine spherical particles around 3–5 nm with high depression. In the composite sample, TiO2 nanoparticles of around 100 nm can be seen to be highly dispersed in the GQDs matrix (Figure 3c). The TiO2 particles in TiO2/GQDs in

Aero-ZnS prepared by physical vapor transport on three-dimensional networks of sacrificial ZnO microtetrapods

• Veaceslav Ursaki,
• Tudor Braniste,
• Victor Zalamai,
• Emil Rusu,
• Vladimir Ciobanu,
• Vadim Morari,
• Daniel Podgornii,
• Pier Carlo Ricci,
• Rainer Adelung and
• Ion Tiginyanu

Beilstein J. Nanotechnol. 2024, 15, 490–499, doi:10.3762/bjnano.15.44

• ], and hybrid composite [26][27] materials. Aeromaterials have been prepared on the basis of sacrificial nano/microstructured templates. Nanofibrillated cellulose has been used as a sacrificial template for the preparation of inorganic nanotube networks, such as titanium dioxide, zinc oxide, and aluminum

Photocatalytic degradation of methylene blue under visible light by cobalt ferrite nanoparticles/graphene quantum dots

• Vo Chau Ngoc Anh,
• Le Thi Thanh Nhi,
• Le Thi Kim Dung,
• Dang Thi Ngoc Hoa,
• Nguyen Truong Son,
• Nguyen Thi Thao Uyen,
• Nguyen Ngoc Uyen Thu,
• Le Van Thanh Son,
• Le Trung Hieu,
• Tran Ngoc Tuyen and
• Dinh Quang Khieu

Beilstein J. Nanotechnol. 2024, 15, 475–489, doi:10.3762/bjnano.15.43

• CoFe2O4/GQDs composite material was placed in flasks sealed with aluminium foil and containing 20 mL of 10 ppm MB solution at pH 3–11, adjusted with 0.01 M HCl or 0.01 M NaOH. After 60 min of adsorption and photodegradation, the tubes were placed in a photocatalytic cabinet for illumination for 120 min

• that the resulting composite can enhance the absorption capacity [11]. This observation is an agreement with previous works [11]. In addition, a slight shift of the PL emission peak is also observed because of the blue shift in the UV–vis spectrum, which is consistent with their bigger bandgap energy

On the mechanism of piezoresistance in nanocrystalline graphite

• Sandeep Kumar,
• Simone Dehm and
• Ralph Krupke

Beilstein J. Nanotechnol. 2024, 15, 376–384, doi:10.3762/bjnano.15.34

• strain within the grains remains constant even though the externally applied strain increased to ca. 0.4%. In an attempt to model piezoresistance in NCG, we have used the tunneling + destruction model for composite materials [24]: The model with five free parameters was fitted to the data as shown in

• tunneling distance, d. The model has been used to explain the piezoresistance for several composite materials [29][30]. Zhao et al. [24] used the model to explain the piezoresistance in nanographene films, although the material is comparable to ours and not a composite material in the original sense. NCG

Modification of graphene oxide and its effect on properties of natural rubber/graphene oxide nanocomposites

• Nghiem Thi Thuong,
• Le Dinh Quang,
• Vu Quoc Cuong,
• Cao Hong Ha,
• Nguyen Ba Lam and
• Seiichi Kawahara

Beilstein J. Nanotechnol. 2024, 15, 168–179, doi:10.3762/bjnano.15.16

• also attracted significant interest. This material with exceptionally high specific surface area, high mechanical properties, and high thermal conductivity is expected to prepare high-performance rubber composites [21][22][23]. In our recent work [24], we successfully designed a DPNR/GO composite by

• of NR composite. The usage of GO-VTES may be suitable for the preparation of NR composites for tire applications as the composite may reduce water permeability and enhance the abrasion resistance of commercial products [30]. Experimental Materials The natural rubber used in this work is high-ammonia

• until neutral. The collected solid was entirely dried in an oven at 50 °C to obtain the final GO-VTES(a) and GO-VTES(b). Preparation of DPNR/GO-VTES composite The DPNR/GO-VTES composite was prepared via graft copolymerization technique using TEPA/TBHPO redox initiators, similar to our previous work [24

Enhanced feedback performance in off-resonance AFM modes through pulse train sampling

• Mustafa Kangül,
• Navid Asmari,
• Santiago H. Andany,
• Marcos Penedo and
• Georg E. Fantner

Beilstein J. Nanotechnol. 2024, 15, 134–143, doi:10.3762/bjnano.15.13

• values can be selected (Figure 2C-i.). However, in the case of composite samples consisting of different materials, using a reference curve taken on one material would create problems when imaging a second material, since different materials exhibit different force curves for the same maximum force

Influence of conductive carbon and MnCo₂O₄ on morphological and electrical properties of hydrogels for electrochemical energy conversion

• Sylwia Pawłowska,
• Karolina Cysewska,
• Yasamin Ziai,
• Jakub Karczewski,
• Piotr Jasiński and
• Sebastian Molin

Beilstein J. Nanotechnol. 2024, 15, 57–70, doi:10.3762/bjnano.15.6

• composite acted as an electrocatalyst in the oxygen evolution reaction. Morphological studies confirmed that the added particles were incorporated and, in the case of a higher concentration of cCB particles, also bound to the surface of the structure of the hydrogel matrix. The produced composite materials

• , drugs, metal nanoparticles, metal oxide nanoparticles, carbon nanotubes, or biomolecules. This is a very important advantage that opens ways of designing composite hydrogels with various properties and applications such as biomedical [8][9][10], biosensors [11][12][13], wearable electronics [14][15][16

• particles of the MnCo2O4 electrocatalyst and conductive carbon in a PNIPAAm hydrogel precursor solution, which was then subjected to polymerisation. As a result, a hydrogel composite was created in a single-stage synthesis process. In addition, the applied methodology allowed us to avoid the need to use

Fluorescent bioinspired albumin/polydopamine nanoparticles and their interactions with Escherichia coli cells

• Eloïse Equy,
• Jordana Hirtzel,
• Sophie Hellé,
• Béatrice Heurtault,
• Eric Mathieu,
• Morgane Rabineau,
• Vincent Ball and
• Lydie Ploux

Beilstein J. Nanotechnol. 2023, 14, 1208–1224, doi:10.3762/bjnano.14.100

• emission related to the bacterial cells. Eight different types of samples were prepared, which are described in Table 2. Molecules of (a) lysine (K) and (b) glutamate (E). (c) Interactions between dopamine and KE sequence. (d) Possible structures of protein (grey)/polydopamine (black) composite particles

Properties of tin oxide films grown by atomic layer deposition from tin tetraiodide and ozone

• Kristjan Kalam,
• Peeter Ritslaid,
• Tanel Käämbre,
• Aile Tamm and
• Kaupo Kukli

Beilstein J. Nanotechnol. 2023, 14, 1085–1092, doi:10.3762/bjnano.14.89

• nanocomposite layer. ZrO2–SnO2 stacked layers have been shown to perform as mechanically elastic and magnetizable films [6]. SnO2-coated carbon nanotubes have been studied as catalysts [7] and ZnO–SnO2 as functional composite in Li-ion batteries [8]. A recent review article from 2022 lists 27 different

Nanoarchitectonics of photothermal materials to enhance the sensitivity of lateral flow assays

• Elangovan Sarathkumar,
• Rajasekharan S. Anjana and
• Ramapurath S. Jayasree

Beilstein J. Nanotechnol. 2023, 14, 988–1003, doi:10.3762/bjnano.14.82

• because of their remarkable ability to absorb light across a broad spectrum and their high PCE. The main classes of photothermal carbon-based nanomaterials are carbon nanotubes, graphene-based nanomaterials, carbon quantum dots, and carbon-based composite materials. Among these, carbon nanotubes have the

• nanoparticles in the composite can increase the light absorption through surface plasmon resonance. Hence, graphene-based multifunctional nanocomposite materials could be employed as promising photothermal agents [44]. Polymer-based nanomaterials: Because of high biocompatibility, high PCE, and facile synthesis

• ]. The photothermal properties can also be enhanced by optimizing the elemental composition of the nanomaterials [44]. Generally, nanocomposite materials are developed by incorporating two or more compounds in a single particle, resulting in enhanced physicochemical properties of the final composite

Metal-organic framework-based nanomaterials for CO₂ storage: A review

• Ha Huu Do,
• Iqra Rabani and
• Hai Bang Truong

Beilstein J. Nanotechnol. 2023, 14, 964–970, doi:10.3762/bjnano.14.79

• , including pore size manipulation, post-synthetic modifications, and composite formation. Finally, the extant challenges and anticipated prospects pertaining to the development of MOF-based nanomaterials for CO2 storage are described. Keywords: CO2 storage; metal-organic frameworks; nanomaterials; open

• amount of absorbed CO2 was significantly improved. Notably, the optimal Mg-MOF-74/graphene-based composite yielded a high CO2 adsorption capacity of 8.4 mmol·g−1 at 298 K and 1 bar. Grand canonical Monte Carlo simulation for CO2 storage prediction Grand canonical Monte Carlo (GCMC) simulation is an

A wearable nanoscale heart sound sensor based on P(VDF-TrFE)/ZnO/GR and its application in cardiac disease detection

• Yi Luo,
• Jian Liu,
• Jiachang Zhang,
• Yu Xiao,
• Ying Wu and
• Zhidong Zhao

Beilstein J. Nanotechnol. 2023, 14, 819–833, doi:10.3762/bjnano.14.67

• University, Hangzhou 310018, China School of Cyberspace Security, Hangzhou DIANZI University, Hangzhou 310018, China 10.3762/bjnano.14.67 Abstract This paper describes a method for preparing flexible composite piezoelectric nanofilms of P(VDF-TrFE)/ZnO/graphene using a high-voltage electrospinning method

• . Composition and β-phase content of the piezoelectric composite films were analyzed using X-ray diffraction. The morphology of the composite film fibers was observed through scanning electron microscopy. Finally, the P(VDF-TrFE)/ZnO/graphene composite film was encapsulated in a sandwich-structure heart sound

• system designed in this paper can collect heart sound signals in real time and predict whether the heart sounds are normal or abnormal, providing a new solution for the diagnosis of heart diseases. Keywords: composite piezoelectric nanofilm; electrospinning; heart sound classification algorithm; heart

Silver nanoparticles loaded on lactose/alginate: in situ synthesis, catalytic degradation, and pH-dependent antibacterial activity

• Nguyen Thi Thanh Tu,
• T. Lan-Anh Vo,
• T. Thu-Trang Ho,
• Kim-Phuong T. Dang,
• Van-Dung Le,
• Phan Nhat Minh,
• Chi-Hien Dang,
• Vinh-Thien Tran,
• Van-Su Dang,
• Tran Thi Kim Chi,
• Hieu Vu-Quang,
• Radek Fajgar,
• Thi-Lan-Huong Nguyen,
• Van-Dat Doan and
• Thanh-Danh Nguyen

Beilstein J. Nanotechnol. 2023, 14, 781–792, doi:10.3762/bjnano.14.64

• release of silver ions or electrostatic interaction between AgNPs and microbial cells, have been proposed [21][22]. The AgNPs might release silver ions capable of binding to nucleic acids, thereby, exhibiting antibacterial activity [23][24]. Consequently, any silver-containing composite material with

• loaded onto the nanocomposite [37][39], followed by reduction using plant extract [36][38]. In the present work, we have developed an in situ synthesis method for AgNPs using an alginate composite with lactose as reducing sugar. This method involves the use of lactose as a negatively charged compound

• additives. The formation of AgNPs was confirmed by a change in the color of the colloidal solution. To find the optimal reaction conditions, the synthesis of the nanocomposite was carried out while varying the reaction conditions, such as temperature, reaction time, and ratio of Ag+ to blank composite

In situ magnesiothermic reduction synthesis of a Ge@C composite for high-performance lithium-ion batterie anodes

• Ha Tran Huu,
• Ngoc Phi Nguyen,
• Vuong Hoang Ngo,
• Huy Hoang Luc,
• Minh Kha Le,
• Minh Thu Nguyen,
• My Loan Phung Le,
• Hye Rim Kim,
• In Young Kim,
• Sung Jin Kim,
• Van Man Tran and
• Vien Vo

Beilstein J. Nanotechnol. 2023, 14, 751–761, doi:10.3762/bjnano.14.62

• /bjnano.14.62 Abstract Metallothermic, especially magnesiothermic, solid-state reactions have been widely applied to synthesize various materials. However, further investigations regarding the use of this method for composite syntheses are needed because of the high reactivity of magnesium. Herein, we

• report an in situ magnesiothermic reduction to synthesize a composite of Ge@C as an anode material for lithium-ion batteries. The obtained electrode delivered a specific capacity of 454.2 mAh·g−1 after 200 cycles at a specific current of 1000 mA·g−1. The stable electrochemical performance and good rate

• robustness, for example, a higher resistance to pulverization than Si, the durability of Ge-based anode is not sufficient for practical applications [14]. To overcome this limitation, nanoscale control and composite design are two effective strategies [15][16][17][18][19]. In addition to various Ge

Metal-organic framework-based nanomaterials as opto-electrochemical sensors for the detection of antibiotics and hormones: A review

• Akeem Adeyemi Oladipo,
• Saba Derakhshan Oskouei and
• Mustafa Gazi

Beilstein J. Nanotechnol. 2023, 14, 631–673, doi:10.3762/bjnano.14.52

• improved electrochemical performance [63][67]. In a recent study, Tang et al. [29] used an ultrasonication and reduction process to combine nanostructured Ag nanoparticles with a MOF (ZIF-67) to fabricate nanopinna-based composite electrochemical sensors for acetaminophen detection. The results showed a

Carbon nanotube-cellulose ink for rapid solvent identification

• Tiago Amarante,
• Thiago H. R. Cunha,
• Claudio Laudares,
• Ana P. M. Barboza,
• Ana Carolina dos Santos,
• Cíntia L. Pereira,
• Vinicius Ornelas,
• Bernardo R. A. Neves,
• André S. Ferlauto and
• Rodrigo G. Lacerda

Beilstein J. Nanotechnol. 2023, 14, 535–543, doi:10.3762/bjnano.14.44

• sensing, as electromagnetic shielding, and as thermoelectric material [32][33][34][35][36][37][38]. Also, Qi et al. reported a liquid-water sensor based on carbon nanotube–cellulose composite films, and, more recently, Goodman et al. reported the scalable manufacturing of nanocomposites for liquid sensing

• [39][40]. Besides, graphene films deposited on cellulose paper and a graphene/cellulose composite were also reported as a solvent sensor material [30][33]. However, most of these works rely on cellulose as a paper substrate or as a thick composite film that cannot be readily employed for large-scale

• composite MWCNTs were mixed with DI water (1% w/v) and sonicated in an ultrasonic bath for 2 h. The obtained suspension was centrifuged for 5 min at 2500 rpm, and the supernatant (0.6% w/v) was reserved. MFC was dispersed in DI water (0.5% w/v) using a Silverson homogenizer (10,000 rpm) for 10 min and then